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The internal flow instability and high pulsation characteristics in the Roots-type hydrogen circulation pump (RHCP) are the main causes of its aerodynamic noise. This study proposes two mathematical models of new deflectors combined in the static domain to improve flow stability and reduce gas pulsations. Meanwhile, this study also compares the simulation results of different cases with a combination of different deflectors and then chooses the best performance case to research with the original model. Results found that placing the V-shaped deflector at the inlet of the rotor domain effectively reduces pressure pulsations in the RHCP at low rotary speeds. The pressure pulsation index at the inlet of the rotor domain decreased by about 26% compared to the original modal, and the outlet pressure pulsation index decreased by about 10%. Additionally, at low rotary speed, the V-shaped deflector significantly reduces the impact of radial clearance leakage flow on the flow characteristics inside the suction chamber, which improves the gas flow characteristics in the suction chamber. These research findings provide new ideas and methods for designing and manufacturing RHCPs. • Analysis of Roots pumps combining both internal flow characteristics and pulsation characteristics. • Two novel deflector structures are proposed for the rectification objective. • The application of deflectors does not affect the volumetric efficiency of pumps. • The deflector reduces inlet pulsation characteristics at low rotation speed. [ABSTRACT FROM AUTHOR]

The worldwide consumption of pistachio nuts has been increasing over the last decades due to their high nutritional value. Given that only split nuts are commercialised, the closed-shell nuts, which account for most of the harvested ones, must be split by mechanical or thermal processes. However, there is hardly any information about the splitting mechanism based on thermal treatments. Accordingly, the thermal splitting of pistachio nuts in conical spouted beds has been approached, and the effect of the air inlet temperature, the draft tube aperture ratio and the air inlet diameter on the splitting mechanism has been analysed. Batch drying tests have been carried out in the proposed technology at an air inlet temperature range of 40–120 ∘ C using configurations with and without draft tube. The operating temperature and dryer configuration that allows attaining up to 60% of split pistachios and preserving their quality are 80 ∘ C , an inlet diameter of 0.05 m and an open-sided draft tube with an aperture ratio of 80%. [ABSTRACT FROM AUTHOR]

Montrose Bay's coastline in Scotland is experiencing the most severe erosions, especially in its southern section, interfacing with the Montrose Tidal Inlet System. This inlet system could induce a distinct ebb tidal jet and eddy when ebbing, influenced by its high-angle half-delta, and the understanding of jet and eddy formation at this type of inlet is still limited. This paper presents the results of a numerical modeling study conducted using Delft3D FM to characterize tidal hydrodynamics at the Montrose Tidal Inlet System, emphasizing the flow features at its seaward side. Acoustic Doppler current profiler measurements captured an asymmetry between peak ebb and flood flow induced by the interaction between the residual of an ebb jet and the alongshore tidal current, which later was successfully replicated by the model, especially after a satellite-derived topography was applied to the Montrose Basin. The observed jet and eddy formation at the Montrose System is unique compared to what has appeared at other inlets with different delta shapes. At spring tides, the jet develops a pair of main and frontal bodies that extend more than 2 km from the inlet and experiences a sharp deflection after interacting with cross current. This jet is accompanied by only one transient eddy with about 1 km diameter at the landward side of the jet frontal. Analysis of residual flow revealed a strong residual going toward the harbor channel at adjacent beaches, which could be contributing to the ongoing sedimentation at the channel. Practical Applications: This study is about a unique coastal current formation at the southern end of Montrose Bay, Scotland, United Kingdom, visualized through numerical modeling. The main feature of this current is a strong outflow, known as the ebb (tidal) jet, which forms during the ebbing phase. This ebb jet expands in the offshore direction before being strongly deflected to the North by the ambient current and simultaneously forming a counter-clockwise eddy within a region between the ebb jet and the beach. This unique coastal current formation is strongly influenced by the configuration between shoreline features, inlet positioning, and the ambient tidal current. This study further explores the potential relevance of this ebb jet and eddy to the ongoing erosion and sedimentation in and around the inlet. Furthermore, this research provides insights into various ebb jet and eddy formations observed at other inlets around the world and highlights the value of utilizing satellite-derived topography data for numerical modeling. [ABSTRACT FROM AUTHOR]

This paper proposes an innovative two-stage ejector with a needle blocking the main nozzle area within 0%-60% to control the mass flow rate of the inlet. Based on this, under certain liquid volume fraction in two-phase inlet fluids, the nozzle exit positions (NXP 1 and NXP 2) and constant-area mixing chamber lengths (L 1 and L 2) of the first and second stages were optimized with blocking area ratio (BAR) of primary nozzle throat by using CFD simulation, the working fluid is R134a. The main results are as follows: (1) The maximum increase rate of the entrainment ratio (ER) of the first and the second-stage with optimization of four geometries without needle blockage are relatively slight, in comparison, both of them with optimization of L 1 can reach 23.47% and 20.38%, which obtain the best improvement; (2) Under the condition of a needle blockage at the primary flow inlet of the first-stage ejector, the increase rate of ER 1 with optimization of NXP 1 and L 1 are close to that without needle blockage; (3) Under the condition of a needle blockage at the primary flow inlet of the second-stage ejector, the first-stage ejector can achieve relatively large improvement of ER, especially, the optimization of NXP 2 can increase the maximum ER 1 by 258.73% of initial value, and the optimization of L 2 can increase the maximum ER 1 by 239.38% of initial value. The study in this work is helpful to understand the two-stage ejector performance improvement by adjusting the blocking area ratio of primary nozzle throat under certain liquid volume fraction in two-phase inlet fluids. [ABSTRACT FROM AUTHOR]

This study investigates the impact of upstream energy deposition as an active flow control method on the performance of a two-dimensional scramjet inlet through numerical simulations. An in-house inviscid finite volume solver was employed for the simulations, with boundary reconstruction of the scramjet achieved using a ghost-cell based immersed boundary method. The effects of different energy spot locations, various energy strengths, and different freestream Mach numbers on the scramjet performance were thoroughly analyzed. Four inlet parameters, namely, mass capture ratio (μ), total pressure ratio (TPR), kinetic energy efficiency (η K E), and flow distortion index (DI), were used to assess the scramjet performance. The analysis revealed that energy deposition significantly reduced flow distortion, resulting in noticeable improvements in mass flux and total pressure ratio. However, kinetic energy efficiency exhibited minimal change. The study provides comprehensive insights into the impact of energy deposition on scramjet performance, highlighting its potential for enhancing inlet characteristics. • Effects of upstream energy deposition on scramjet inlet performance are numerically investigated. • Scramjet performance is assessed using four aerothermodynamic parameters. • Upstream energy deposition significantly reduces flow distortion and improves mass flux. • The location and strength of the deposited energy strongly influence the performance parameters. [ABSTRACT FROM AUTHOR]

We study the capability of Large Eddy Simulation (LES) to predict fluid residence time in a ventilated room. Validation is performed against an experiment where the inlet vent slot width matches that of the room. On a coarse grid, the Smagorinsky subgrid-scale model has a detrimental effect on flow statistics, whilst the WALE and Germano–Lilly models perform well. A refined grid produces close agreement with the reference data. A simulation with a narrow inlet slot demonstrates that the flow becomes three-dimensional, with pairs of spiral vortices forming in the room and altering the recirculation pattern when compared to the wide inlet slot configuration. The obtained LES statistics show improvements in the prediction of velocity field over conventional RANS modelling techniques. Fluid age probability density functions show that a wide range of residence time values around the mean value can be observed within the room. LES is capable of providing accurate predictions in a simplified ventilated room, and residence time probability density function distributions can be useful for the improvement of ventilation strategies. [ABSTRACT FROM AUTHOR]

A three-dimensional numerical study is performed to investigate the effect of inlet mass flow rate on flow field characteristics and pressure gain of rotating detonation combustor. The results show that the mass flow rate has an important effect on the behavior of the detonation wave. When the inlet mass flow rate is increased, the flow Mach number of inlet throat increases and flow develops to a close critical state. After ignition, two counter-rotating detonation waves will collide in the combustor and the number of collisions decreases with the increase of inlet mass flow rate. The strong wave eventually engulfs the weak wave and develops into a single-wave mode. When the inlet mass flow rate is reduced, the detonation wave velocity and refill height of premixed gas increase. Deflagration area of flow field reduces and the stability is improved. In addition, when the inlet mass flow rate is reduced, the total pressure loss caused by expansion wave decreases. The pressure gain and fuel-based specific impulse are increased. However, increasing the total pressure gain also improves the static pressure fluctuation ratio of inlet throat. The phenomenon of high-pressure feedback under small flow rate condition is also more prominent. [ABSTRACT FROM AUTHOR]

In this paper, we theoretically investigated the thermal performance of a low-pressure cryogenic vaporizer for liquified hydrogen supply system. A performance analysis model was developed by the modified effectiveness-NTU method considering the axial conduction and phase change of liquified hydrogen. In the analysis model, a plate-fin heat exchanger (PFHE) was chosen as the type of a cryogenic vaporizer. The inlet temperature and pressure conditions of liquified hydrogen were 20 K and 10 bar, respectively and the outlet temperature condition of hydrogen was a room temperature. Based on the theoretical results, we presented effects of geometric parameters on the performance of the vaporizer under the fixed pumping power condition. Especially, it is shown that the effectiveness of the hot fluid and cold fluid exhibit opposite trends depending on the axial conduction. In addition, we presented the effect of the aspect ratio of microchannels on the effectiveness considering both cases where the microchannel heights of the EGW mixture and hydrogen were either the same or different. Also, we showed the effect of the vaporizer length on the performance of the vaporizer. Finally, geometric parameters that can satisfy the two target performances are suggested. • Thermal performance of a low-pressure cryogenic vaporizer for liquified hydrogen was investigated. • Modified effectiveness-NTU method considering the axial conduction and phase change of liquified hydrogen were used. • Effectiveness of the hot fluid and cold fluid exhibit opposite trends depending on the axial conduction. • Effects of the aspect ratio of microchannels and the length on the effectiveness were presented. [ABSTRACT FROM AUTHOR]

This study uses the Large Eddy Simulation (LES) technique to conduct an exhaustive analysis of the flow characteristics within the Rectangular-to-Elliptical shape Transition (REST) inlet under Mach 6 conditions. It mainly focuses on investigating the influence of the shock wave-turbulence interaction on the swirl distortion at the inlet exit. At the design condition, characterized by 0° Attack and 0° Sideslip, the incident shock wave at the inlet lip undergoes multiple reflections within the boundary layer of the domain wall, culminating in the formation of turbulent structures. The first reflected shock wave has the highest energy, exerting a significant impact on the boundary layer and the exit swirl distortion. On the contrary, the energy of the incident shock wave is progressively reduced due to repeated reflections, which results in reducing the exit swirl distortion. Under off-design conditions, characterized by 6° Attack and 0° Sideslip as well as 6° Attack with 6° Sideslip, variations in the incoming flow make the incident shock wave move inward, decreasing the frequency of shock wave reflections and even significantly reducing the reflected shock waves under conditions of 6° Attack and 6° Sideslip. However, this results in significantly increasing the exit swirl angle and distortion intensity. The obtained results demonstrate that changes in the incoming flow conditions significantly affect the level of exit swirl distortion by modulating the shock wave-turbulence interaction, especially in terms of the positioning of the incident shock wave and the quantity of reflected shock waves. In addition, this paper studies the wall heat transfer coefficient of the inlet. The obtained results show that the interaction between shock waves and the boundary layer significantly affects the heat transfer coefficient. This study provides a foundation for the comprehension and prediction of the performance of hypersonic inlets across a spectrum of flight conditions, and for the guidance of the design and optimization of such inlets. [ABSTRACT FROM AUTHOR]

Objective: For degenerative diseases accompanied by cervical malalignment, the starting and ending points of fixation for better cervical sagittal alignment and clinical results are not as clear as the thoracolumbar region. In this study we aimed to compare the effects of posterior subaxial cervical fixation (PSCF), posterior cervical fixation extending to the upper thoracic region and posterior upper cervical fixation extending to the upper thoracic region on cervical sagittal alignment. Methods: Sixty‐three patients who underwent posterior cervical and cervical‐up thoracic fixation were retrospectively analyzed in a comparative study. The procedures that we performed from May 2019 to March 2022 on these 63 patients were: (1) C3‐C6 group—posterior subaxial cervical fixation; (2) Subaxial‐T2 group—posterior subaxial cervicothoracic fixation (PSCTF); (3) C2‐T2 upper thoracic posterior fixation group. The C3‐C6 group had 27 patients, Subaxial‐T2 group had 24, and C2‐T2 group had 12. We determined the minimum follow‐up period as 12 months. C0‐2, C2‐7 lordosis angle, sagittal vertical axis (SVA), C2 slope, C7 slope, T1 slope, cervical slope, neck slope, and thoracic inlet angle (TIA) measurements were made in three patient groups. Comparatively, cervical sagittal alignment was evaluated. Result: In the C2‐T2 group, a significant increase in C2‐C7 lordosis, decrease in C2 slope, and increase in TS‐CL were observed. Significant C2‐C7 lordosis decrease, C2 slope increase, and TS‐CL decrease were observed in the C3‐C6 group. A significant increase in C2‐C7 lordosis and a decrease in C2 slope were observed in the subaxial‐T2 group. No significant change was observed in the TS‐CL angle. Conclusion: In cervical degenerative disorders accompanied by cervical malalignment, we recommend the C2‐T2 fixation method, which provides the desired C2‐C7 lordosis, SVA within the normal range, and the best Neck Disability Index results. [ABSTRACT FROM AUTHOR]

Chip breakers are used in turning to improve chip breakage. In standard cutting inserts, they are pressed into the rake face before sintering. However, for specialized tools like profile grooving tools, this pressing is not possible. Instead, a laser preparation process can be applied after grinding the tool profile to create a diverse range of chip breaker geometries. The aim of this investigation is to gain insights into the relationship between the geometric parameters of laser-prepared chip breaker geometries and chip formation. For this reason, experimental turning investigations were conducted with varied chip breaker geometries. Based on these experiments, chip formation was observed for different profile geometries and chip breakers. The findings indicate that the inlet angle, outlet angle, width, depth, and lateral ridges significantly influence chip-breaking behaviour. These results can inform the development of application-specific design for chip breaker geometries. [ABSTRACT FROM AUTHOR]

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Metal Working (1674-165X) is the property of Metal Working Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Irrigation & Drainage is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Short‐circuiting in secondary clarifiers is a well‐known problem that can occur through up‐flow or underflow routes. The underflow short‐circuiting is not as visible as up‐flow short‐circuiting but can affect clarifier performance. The energy‐dissipating inlet (EDI) is a type of inlet structure that is used in secondary clarifiers to dissipate the energy of larger influent volumes, allowing clarifiers to operate at higher treatment capacities. The underflow short‐circuiting is encountered particularly in clarifiers equipped with EDIs. As influent volume increases, conventional draw‐off pipes cannot handle high sludge capacities, deforming the sludge blanket and leading to lower concentration of solids being withdrawn. Retrofitting the design of draw‐off pipes is an effective way to mitigate underflow short‐circuiting and enhance treatment performance. In this study, a snail‐shaped sludge draw‐off pipe was designed and tested in two types of EDIs using computational fluid dynamics tools, showing a 20% increase in withdrawn sludge concentration and mitigating underflow short‐circuiting potential. The optimal retrofit option was identified as equipping the clarifier with a snail‐shaped draw‐off pipe and an innovative EDI, known as multilayer EDI column, which would save almost half of the energy and operational costs of the biological processes while meeting discharge limits. [ABSTRACT FROM AUTHOR]

To solve the problem that the control of shock wave elimination is weakened under off-design conditions, the design concept of a variable-geometry inlet scheme that combines the variable-geometry cowl (translating and diagonalizing) with regulating shock wave elimination is introduced in this paper. The variable-geometry inlet is designed by the theories of oblique shock wave and isentropic wave as well as the Oswatitsch theory. Regulatory law of the variable-geometry cowl based on shock wave elimination is obtained by the geometric relationships between cowl compression angle, cowl shock wave angle, and optimal control point or range. Numerical simulations are conducted to investigate flow field characteristics, control mechanism, and working performance of the inlet. Results reveal that expansion waves have a significant impact on the cowl shock wave and boundary layer interaction, and flow separation. Furthermore, variable-geometry inlet with translating and diagonalizing cowl based on the regulation of shock wave elimination effectively controls and even completely eliminates the flow separation. In terms of inlet performance, the total pressure loss of the variable-geometry inlet decreases such that the total pressure recovery coefficients of the translating cowl and diagonalizing cowl inlets are increased by maximum values of 3.39 % and 9.97 %, respectively. However, the mass flow coefficient of translating cowl inlet decreases, whereas that of the diagonalizing cowl inlet is equivalent to that of the fixed-geometry inlet. The working range can be widened by changing the internal contract ratio of the inlet through translating or diagonalizing the cowl. The results confirm that the scheme of variable geometry inlet with diagonalizing cowl is practicable and reliable and has important guiding significance and value for inlet design. [ABSTRACT FROM AUTHOR]

In this paper, the hydrogen direct reduction of iron ore fines is numerically studied by using the Dense Discrete Phase Model (DDPM) in the fluidized bed. The fluidization behavior at different inlet gas velocities (Ug) as well as the influence of Ug and hydrogen concentration on reduction degree (RD) are comprehensively investigated. The result indicates the increase of time-averaged solids volume fraction for the same cross-sectional heights with increasing Ug when the bed height (H) exceeds 0.06 m. Furthermore, the reduction rate of mineral powder increases with higher Ug value, and the RD reaches almost 100 pct after 4000 seconds of reduction time with Ug ranging from 0.35 to 0.65 m/s. The reduction rate increases noticeably with the increase of hydrogen concentration in the range of 10 to 100 pct, and Fe2O3 can be completely converted to Fe under condition of 65 pct H2 concentration after 4000 seconds. Moreover, higher H2 concentration leads to faster rate of Fe2O3 consumption and Fe production. The mass fraction peak values of Fe3O4 and FeO are in the range of 0.29 to 0.34 and 0.21 to 0.24 under different H2 concentrations, respectively. [ABSTRACT FROM AUTHOR]

Limited experimental research has been conducted on organic Rankine cycle (ORC) systems that use wet working fluids. Therefore, the present study examined how the performance of an ORC system that uses a wet working fluid (R134a) was affected by the superheat degree ratio (SDR) under various scroll rotation speeds. The SDR is the dimensionless ratio between superheat degree and evaporation temperature at a given heat source temperature. Experimental results indicated that at scroll rotation speeds of 900, 1350, and 1800 rpm, the maximum output power of the aforementioned system was 1103, 1464, and 1537 W, respectively, with SDRs of 0.49, 0.49, and 0.54, respectively. The maximum net efficiencies at these speeds were 5.87%, 5.91%, and 5.32%, respectively, which occurred at SDRs of 0.61, 0.49, and 0.48, respectively. This level of system performance was attributable to the high enthalpy at the expander inlet and the high mass flow rate at the high evaporation pressure under an SDR of approximately 0.5. Although increasing the SDR did not enhance the scroll expander's isentropic efficiency, this efficiency decreased considerably when the SDR fell below 0.2. These findings emphasize the importance of optimizing the SDR of ORC systems to improve their performance. [ABSTRACT FROM AUTHOR]

This article presents results from research whose purpose is to determine the impact of two main factors on the operational efficiency of a double-entry centrifugal pump. The first factor is the design methods, and the second is changes in the geometric parameters for the volute casing. The results of the numerical simulation were experimentally validated on a test stand. Within this study, volute casings were designed according to the constant velocity method and method of conservation of angular momentum of the flow. The geometric parameters were selected according to the recommendation of A. Stepanoff and A. Lomakin. Next, the following geometric parameters were changed: inlet diameter, inlet width, cross-sectional area, shape of the volute casing's cross-section (trapezoidal vs. round) and the opening angle of the volute casing's walls. A comparison of the two methods showed that the biggest difference between them is the influence on the shape of the pump characteristic curve. Altering the geometric parameters in trapezoidal or round volute casing cross-sections had minimal impact on the pump head and efficiency. [ABSTRACT FROM AUTHOR]

This paper studies state observation for a heterogeneous quasilinear traffic flow system with disturbances at the inlet of a considered road section. Based on the backstepping method, an observer is designed for the quasilinear traffic flow system with only the boundary measurements at the inlet of the considered road section. The observer is constructed by duplicating the quasilinear system and adding the output injection terms to the partial differential equations and boundary conditions. Making use of the backstepping transformation, the injection gains of the observer system are derived by the computation of kernel equations, which are obtained by mapping the error system into an integral input-to-state stable target system. The applicability of the observer for the design of an output feedback controller stabilizing the quasilinear system is discussed. Finally the assumptions of the design of the observer are numerically checked on a realistic congested traffic scenario. [ABSTRACT FROM AUTHOR]

In this paper, a novel air‐cooled supercapacitor thermal management system (STMS) based on the corner deflectors and the inclined inlet and outlet was proposed. The temperature and velocity fields were simulated and analyzed by CFD. Moreover, the heat dissipation effect of different STMSs was analyzed against each other. The results showed that the STMS proposed had a better heat dissipation effect when the inclined angle of inlet and outlet was appropriate, in which the maximum temperature (Tmax) and the maximum temperature difference (ΔTmax) of the module could be reduced by 10.3% and 34.6%. And it is shown that the structure with inclined inlet and outlet plays an important role for the heat dissipation capability of the STMS proposed. And it has experimentally proven its heat dissipation ability. Consequently, the impacts of inclined angle (α), monomer spacing (dc), and the distance between monomer and module shell (dx, dy, and dz) on the heat dissipation effect were deeply analyzed. For the STMS arranged in four rows and three columns, it had a better heat dissipation effect when inclined angle was in the range of 40° to 50°. The results showed that the structural parameters had a large influence on the Tmax and ΔTmax. Besides, it had shown that the temperature curves of the Tmax and ΔTmax had a main trend of "decreasing and then increasing" when the monomer spacing as well as the distance between monomer and module shell are taken from 1 mm to 5 mm. It implies that a small spacing (1 mm to 2 mm) will hinder the air circulation and reduce heat dissipation, and a large spacing (3 mm to 5 mm) will reduce the average flow rate of air and reduce the efficiency of heat transfer. [ABSTRACT FROM AUTHOR]

The stable combustion of rotating detonation engines is significantly affected by inlet spatial fluctuation, especially during aircraft maneuvering, necessitating extensive research for further engineering enhancements. This study analyzes the effect of the spatial fluctuation of inlet total pressure on the propagation characteristics and evolution mechanisms of rotating detonation waves. The in-house solver, BYRFoam, based on the OpenFOAM platform, is utilized. The velocity deficit of detonation waves is discussed under the different inlet spatial fluctuations of mean total pressure, instability degree, and spatial frequency. The results indicate that the propagation process of detonation waves is divided into wave mode transition and operating mode-locked stages; the latter consists of the self-adjustment stage, low-frequency instability stage, and dynamic equilibrium stage. A dynamic equilibrium mechanism is proposed, which is the self-adjustment process of detonation waves, counter-rotating shock waves, and striped fresh gas, encompassing the stages of strong and weak detonation. Furthermore, the oscillation phenomenon of the peak pressure, frequency, and velocity of detonation waves is seriously related to spatial fluctuation, leading to instability during detonation wave propagation. The instability phenomenon in this study is compared with the experimental data, providing valuable theoretical support for engineering applications involving rotating detonation engines. [ABSTRACT FROM AUTHOR]

Geometric deviations arising from manufacturing and assembly processes can significantly impact the aerodynamic stability of scramjet inlets. This study aims to quantify the uncertainty and sensitivity of the inlet aerodynamics caused by geometric deviations. Specifically, three representative operating modes are considered: start, half-start, and unstart. Five geometric parameters are extracted as random uncertain variables, including the first and second ramp angle (α1, α2), the horizontal and vertical distance between the lip point and the throat point (dh, dv), and the inner angle of the cowl lip (α3). To achieve the quantification objective, the non-intrusive polynomial chaos method is employed for uncertainty quantification. Sobol indices are utilized to assess the impact of each geometric parameter on the uncertainty of quantities of interest. Results indicate that geometric deviations for only ±1% can have a significant impact on the aerodynamic performance of the inlet. Specifically, the pressure uncertainty in the shock region is more than four times that of the non-shock region, exceeding 40%. With respect to the performance parameters, the mass capture ratio demonstrates a high sensitivity to geometric deviations, with the uncertainty for 6.76%. Sensitivity analysis indicates that the three primary factors affecting the aerodynamic stability within the isolator are dv, α2, and dh. Therefore, deviations in their manufacturing and assembly should be strictly controlled. [ABSTRACT FROM AUTHOR]

The dynamic flame behaviors at the preliminary stage of ignition in the mesoscale sudden-expansion channel are numerically investigated in this study under the isothermal condition (300 K) at walls by using a two-dimensional model without symmetric assumption at the centerline. It is found that the flashback velocity is dominated by the upstream channel height; nevertheless, the blowoff velocity is determined by not only the downstream channel height but also the flow recirculation behind the sudden-expansion steps. As the expansion ratio is sufficiently large, the flame could exist within a substantially wider range of inlet flow velocity. In addition, four types of flame behaviors are found at the expansion ratio of 2: (I) steady convex flame, (II) steady concave flame, (III) simple oscillating flame, and (IV) complex oscillating flame. Above the flashback velocity, the convex flame exists steadily. With the increase in flow velocity, the flame becomes concave to the upstream and is stabilized by the wall-quenching effect of sudden-expansion steps. If the flow velocity is further increased, the flame becomes unstable and oscillates periodically (simple oscillating flame) due to the interaction of flame and the symmetric flow field in the sudden-expansion channel, while the occurrence of complex oscillating flame at high flow velocities is attributed to the asymmetric flow pattern. The frequency of oscillating flames decreases with the increase in flow velocity. [ABSTRACT FROM AUTHOR]

Dry powder inhalers (DPIs) are widely employed to treat respiratory diseases, offering numerous advantages such as high dose capacity and stable formulations. However, they usually face challenges in achieving sufficient pulmonary drug delivery and minimizing excessive oropharyngeal deposition. This review provides a new viewpoint to address these challenges by focusing on the role of swirling flow, a crucial yet under-researched aspect that induces strong turbulence. In the review, we comprehensively discuss both key classic designs (tangential inlet, swirling chamber, grid mesh, and mouthpiece) and innovative designs in inhalers, exploring how the induced swirling flow initiates powder dispersion and promotes delivery efficiency. Valuable design considerations to effectively coordinate inhalers with formulations and patients are also provided. It is highlighted that the delicate manipulation of swirling flow is essential to maximize benefits. By emphasizing the role of swirling flow and its potential application, this review offers promising insights for advancing DPI technology and optimizing therapeutic outcomes in inhaled therapy. [Display omitted] [ABSTRACT FROM AUTHOR]

In the present study, the energy, exergy, environmental, and economic (4-E) analyses of Rajai's combined cycle power plant with applying environmentally friendly technologies have been performed. To this end, three scenarios have been considered: (1) without auxiliary systems; (2) with modified guide vane system; (3) integrated guide vane system and inlet air fogging. The angle was increased from 84 $$^\circ $$ ∘ to 86 $$^\circ $$ ∘ to modify the guide vane opening angle of the compressor. Besides, inlet air fogging is used to reduce the compressor's inlet temperature. The results show that the highest exergy destruction ($$\~34\% $$ \~ 34 %) occurred in the combustion chamber. The corresponding values for HRSG and gas turbine are 21% and 26%, respectively. With a modified guide vane system, scenario 2, the cycle's first law efficiency is enhanced by 0.56% compared to scenario 1. In addition, in scenario 3, the second law efficiency increased by 0.67%, and the exergy destruction decreased by 0.85%. By using the proposed system, an increased income of $${h_i}$$ h i .85 per megawatt-hour was gained. Regarding the $$C{O_2}$$ C O 2 emission and fuel consumption, a reduction of 1.65% and 1150 $${m^3}/h$$ m 3 / h was observed. [ABSTRACT FROM AUTHOR]

This study experimentally investigated the temporal evolution of the scour parameters downstream of a trapezoidal piano key weir. The densimetric Froude number (Frd50) in the range of 0.39–0.57 and the relative vertical distance of the sediment bed level to the weir toe (Δz/P) in the range of 0.025–0.5 were taken into consideration. In general, with an increase in Frd50, the scouring rate, maximum scour depth, scour hole area and scour hole volume enhanced over time. The increases in the scour parameters were greater at the initial stages of the tests. About 87, 80, 65 and 70% of the maximum scour depth, weir toe scour, scour hole area and scour hole volume occurred within the first 20% of the durations of the tests, respectively. Any increase in Frd50 and Δz/P augmented the scour depth at the weir toe. The results also indicated that the distance of maximum scour depth from the weir increased for greater values of Δz/P and Frd50. The amounts of scour downstream of the outlet keys were greater than those downstream of the inlet keys. The trend of variations of the longitudinal bed profiles remained nearly unchanged over time. New equations were developed to predict the temporal variations of scour parameters, with acceptable accuracy. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Drainage & Irrigation Machinery Engineering / Paiguan Jixie Gongcheng Xuebao is the property of Editorial Department of Drainage & Irrigation Machinery Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Rural Water & Hydropower is the property of China Rural Water & Hydropower Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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A simple explicit formula for evaluating the total capacity of chilled-water cooling coils under wet conditions is reported in this paper. The formula is developed through theoretical and analogical analysis from a practical viewpoint. With the formula, a wet coil's total cooling capacity can be predicted straightforwardly, given the inlet air and water conditions. The formula was cross-validated against a set of catalog performance data from a series of fan coil unit (FCU) coils and simulated performance data from a series of air handling unit (AHU) coils. The mean errors in the calculated results of the present formula did not exceed 5% in the training and test sets for each coil, showing it has good accuracy and generalizability over a wide operating range and various coil types. This formula is expected to have wide applications in energy simulation and control optimization of building air-conditioning systems. [ABSTRACT FROM AUTHOR]

Steam stripping of ammonia from ammonia-rich wastewater (5000–20,000 mg/L) was conducted in a continuous-flow rotating packed bed (RPB) at a pH of 11. This study aimed to elucidate the influence of key operational parameters, including the steam-to-liquid ratio, rotational speed (ω), initial ammonia concentration, steam inlet temperature (TSi), and liquid inlet temperature (TLi), on critical performance metrics such as the ammonia removal efficiency (ARE), the volumetric liquid mass transfer coefficient (KLa), and the concentration of the recovered ammonia solution (CR). The findings revealed that a CR of 22.88 wt.% was achieved under the optimal conditions of a steam-to-liquid ratio of 0.175 kg/kg, an initial concentration of 20,000 mg/L, a TSi of 120 °C, and a TLi of 70 °C. Key experimental factors, including the initial ammonia concentration, TSi, and TLi, significantly impacted the achievement of higher ARE and CR values. The KLa values exhibited a decrease with the increase in the steam-to-liquid ratio, while they increased with ω. However, the KLa remained relatively consistent with ω values within the range of 600 to 1200 rpm. In comparison with prior studies, steam stripping of ammonia exhibits a higher ARE than air stripping with RPB and a higher CR than conventional stripping methods. Moreover, RPB requires a smaller size to achieve equivalent ARE compared to conventional stripping apparatuses. Thus, the steam stripping process with RPB equipment emerges as a suitable method for ammonia recovery from ammonia-rich wastewater. [ABSTRACT FROM AUTHOR]

The northern inlet channel to Jezero crater (Sava Vallis) terminates in a fan‐shaped depositional feature, part of which blends into the separate well‐known western fan delta that is the field site for the Mars 2020 mission's Perseverance rover. Jezero's northern fan potentially represents either a second fan delta within the crater or a distal portion of the western fan. To constrain the fluvial and sedimentological history of Jezero and place the rover's in situ observations in proper geologic context, we photogeologically map the northern fan deposits at a larger mapping scale than previous studies, using ground‐based imaging from the Perseverance rover for context. Fifteen map units are identified using HiRISE‐based interpretations of geologic characteristics and inferred processes as well as crosscutting relative age relationships. Mapped units are also defined based on orbital data from CRISM and THEMIS to assess their compositional signatures. We interpret the northern fan deposits as older than the uppermost blocky unit in the western fan delta, suggesting that they were deposited contemporaneously with or prior to the deposition of the western fan, and under similar climate conditions. The eastern portion of the northern fan deposits shows evidence of fluvial deposition from Sava Vallis, while part of its western side could represent a distal part of the western fan delta. We synthesize our interpretations to present scenarios for the deposition of the northern and western fans, which can help constrain the history of both watersheds and place it into context within the broader Isidis basin region. Plain Language Summary: The Mars 2020 Perseverance rover has primarily focused on using its scientific instruments to study the delta along Jezero crater's western margin. But there are fan‐shaped features that appear to originate from both the crater's western and northern channels ‐ Neretva Vallis and Sava Vallis, respectively. In this project, we compile orbital images, spectroscopy data sets, and images taken by the rover's Mastcam‐Z instrument to investigate whether the northern fan originated from the northern channel or is an outlying part of the western delta. Based on these observations and the geologic map created using them, we show that the northern fan deposits are older than the uppermost unit mapped in the western delta. We also demonstrate how the western portion of the northern fan deposits could be an outer part of the western delta, while the eastern portion may preserve material from Sava Vallis. We show that some units across the northern and western fans are the same or similar, making this work useful as the rover's mission continues. Finally, we present scenarios that could lead to what we see in Jezero today, helping us to understand the potential history of this area and the relationship between the northern and western watersheds. Key Points: Deposition of Jezero crater's northern fan predates that of its western fan blocky material—the western delta's uppermost surficial unitThe northern fan shows evidence of deposition from Sava Vallis, but part of its western region could be a distal part of the western deltaThe stratigraphic and depositional hypotheses presented provide context for the Mars 2020 mission and help constrain the history of both watersheds [ABSTRACT FROM AUTHOR]

The current study proposes a novel design configuration of a hydrogen-fueled micro cylindrical combustor. The newly developed design consists of a single-channel inlet and a double-channel outlet with a heat-recirculating structure aimed at enhancing the heat transfer mechanism from the combustion to the walls. Investigations are conducted using three-dimensional numerical simulation means, and emphasis is placed on assessing the effects of the novel design structure on key thermal parameters and nitrogen oxide (NOx) emissions. The numerical modeling approach is first validated against the experimental and numerical data available in the literature. A parametric study is then conducted by means of varying the length and width of the heat-recirculating channel, inlet velocity, and inlet equivalence ratio. The findings revealed that the novel design configuration significantly improves thermal performance and curtails NOx emissions in comparison with those of the conventional structure. For example, the proposed design leads the radiation efficiency to increase by roughly 10%. The increase in the width of the preheating channel yields further optimization by boosting the heat transfer process from the flame to the walls. Elevating the inlet velocity exhibits a pronounced increase in the mean wall temperature and a more uniform distribution of the wall temperature. However, the exhaust gas temperature increases with increasing inlet velocity, leading to a reduction in the exergy and radiation efficiencies. The equivalence ratio of unity optimizes key thermal parameters, as the lean and rich conditions suffer from low hydrogen and oxygen contents, respectively. [ABSTRACT FROM AUTHOR]

Multi-inlet cyclone separators can play a vital role in industrial processes by enhancing particle separation efficiency and minimizing energy consumption. This numerical study investigates multi-inlet cyclone separators to enhance their performance using a constant flow rate with a varying inlet height and width. By systematically varying the inlet height and width, three-inlet and four-inlet cyclone separators are developed and evaluated, termed 3 inlet-a, 4 inlet-a, 3 inlet-b, and 4 inlet-b. The findings reveal that increasing the number of inlets without changing the total inlet area does not improve the separation performance. However, strategic modifications to the inlet height and width significantly enhance the separation efficiency. Notably, the 3 inlet-a and 4 inlet-a designs achieve higher separation efficiencies at a 1.22 m 3 /s flow rate without increasing the pressure drop. Meanwhile, the 3 inlet-b and 4 inlet-b models demonstrate superior performances, with a higher separation efficiency and a pressure drop only marginally higher than the two-inlet design. This study provides valuable insights into the impact of inlet variations on cyclone separator performance, guiding future efforts to enhance the separation efficiency in multi-inlet designs. [ABSTRACT FROM AUTHOR]

In urban signalized intersections, because of the mixing of straight-going and right-turn vehicles in the straight-right shared lane, the straight traffic may block the rear right-turn vehicles from crossing the intersection during the red light, resulting in additional waiting time for right-turn vehicles. To address this problem, this study proposed the dynamic straight-right lane (DSRL) design and corresponding signal control schedule, which separates the straight-going and right-turn vehicles in space–time, making vehicles enter the intersection in an orderly manner. Then, the key parameters of the signal timing scheme were identified, and the physical significance of the key parameters of the optimal signal timing and the calculation models were given by discussing the optimal process of traffic flow operation at the signalized intersection. Finally, taking a realistic T-shaped signal intersection inlet lane as an example, the simulation verification platform was built by VISSIM to analyze the effects of variables on the performance of the DSRL proposed in this study. The results showed that the design proposed in this study can significantly reduce the right-turn vehicle delay without changing the overall layout of the signal intersection, and the total delay optimization rate at the intersection can always reach 10%–30%. [ABSTRACT FROM AUTHOR]

Runway crossing behind an aircraft has attracted a large amount of interest in recent years. In this work, based on a turbofan engine model, three-dimensional models of the nozzle and inlet are established, and the effects of the jet of the aircraft in front on the inlet of the aircraft behind are studied under different operating conditions using numerical simulations. The results show that at the same distance between the two aircraft, the total pressure decreases as the exit flow rate of the inlet increases, but different flow rates do not lead to different component distributions. For the same flow rate at the exit of the inlet, when the distance increases, the distortion index of the total pressure at the exit of the inlet decreases, and the contents of the component of the airflow entering the inlet from the jet decrease, but those entering the inlet from the far field increase. Through component and isotope identification, the main components of the airflow entering the inlet are oxygen and nitrogen. Based on these results, when studying the effect of the exhaust jet from an aircraft on an aircraft behind, only the maximum idle engine speed needs to be considered, and the effect of the jet components on the inlet can be ignored. The inlet distortion caused by the exhaust flow is more severe in crosswind environments. [ABSTRACT FROM AUTHOR]

In laser powder bed fusion (L-PBF) manufacturing, inert gas flow aids in removing spatters and fumes generated during laser-material interaction, ensuring quality of fusion and consequently, the quality of the manufactured parts. This study examines gas flow homogeneity's impact on part quality across the build plate. To do this, gas velocity mappings near the manufacturing plate (XY plane) and at four heights (Z-axis) were performed on a Renishaw AM400 machine using a Pitot tube and a hot-wire anemometer. Four gas inlet configurations are compared to maximize the permissible velocity at the build plate level (1 to 2 m/s) with the constrain of preventing the powder bed from being blown away. AlSi10Mg aluminum sample density measurements served as performance indicators, to quantify the effect of gas flow variations, taking into account their positions within the manufacturing bed. High-speed camera observations and numerical simulations supplemented the analysis. Results indicate gas flow inlet arrangement significantly influences flow homogeneity, reducing non-uniformity by almost 40%. Porosity is also reduced by around 20% and porosity variations on the build plate are reduced by more than 25%. Sample density increases primarily at the plate center and farthest from the gas inlet. Areas closest to the inlet show no significant density change compared to the standard configuration. [ABSTRACT FROM AUTHOR]

Critical heat flux (CHF) is one of the most concerned thermal hydraulic phenomena in reactor safety analysis. It involves complex two-phase flow heat transfer mechanism, and has not been fully understood, so the prediction of critical heat flux mainly depends on CHF correlations obtained under limited experimental conditions. At present, CHF correlations are generally developed with pressure, mass flux and quality as key independent variables. And correspondingly, the test matrix of a CHF test consists of the above parameters. However, it is impossible to perform CHF tests accurately according to the predetermined quality. In CIAE, a CHF experimental research of a 5 χ 5 uniformly heated rod bundle has been carried out. In the experiment, the inlet temperature of the test section was directly taken as a parameter in the test matrix. The CHF data were achieved by stepwise increasing the heating power. The test conditions covered the pressure of 2.8-15.5 MPa, the mass flux of 845-3533 kg/(m2-s), and the inlet temperature of 100°C-300°C. The test data have been analyzed to obtain the thermal-hydraulic parameter influences on CHF by taking the inlet temperature as a variable. The results indicated that, within the test condition range, under the same inlet temperatures, CHF was hardly affected by pressure, and linearly increased with the increasing mass flux. With the increase of inlet temperature, the enhancement of CHF with the increasing mass flux gradually weakens. And CHF was linearly decreased with the increasing inlet temperature under the same mass flux. By contrast, the parameter influences on CHF were more complex by taking the local quality as a variable. According to the research, it can be concluded that, it has an advantage of simplifying the CHF correlation form to take the inlet temperature of the test section as a variable parameter. The research can provide new ideas for CHF experiment, data analysis and correlation development. [ABSTRACT FROM AUTHOR]

According to the relevant basic data of port area and fishing port in Nantong coastal zones, the navigation safety risk of commercial vessels and fishing vessels in Xiaomiaohong Channel was analyzed, and the layout scheme of route of fishing vessel and precautionary area was discussed. The results show that the turning section of Sanjiasha South Channel, which coincides with the habitual route of fishing vessels in Dongzao Fishing Port, has large cross-flow and complex navigation conditions, and the navigation safety risk is relatively high. The route of fishing vessel along the natural inlets on the east side of channel or the relocation scheme of Dongzao Fishing Port can be considered. There is a certain navigation safety risk in the intersection of the habitual route of fishing vessels in L俟si Central Fishing Port and Haozhi Port with Xiaomiaohong Channel. Precautionary areas can be set up to guide the navigation order and improve the navigation environment at the intersection of commercial vessels and fishing vessels. [ABSTRACT FROM AUTHOR]

The unsteady flow field in the aerostatic bearing always induces micro-vibrations, which are severely detrimental to the stability and precision of the bearing. Extensive research has been conducted on the mechanism of micro-vibration, but a consensus has not yet been reached. To this end, the large eddy simulation (LES) and proper orthogonal decomposition methods were employed to analyze the flow field of an annular aerostatic bearing in this paper. A mechanism for inducing micro-vibration and the identification of a novel flow behavior were ultimately revealed. First, the accuracy of our LES method has been validated through quantitative comparison with experimental data. Then, the mode decomposition has been conducted to analyze the flow field under various gas supply pressures. The results demonstrate that when the supply pressure Ps = 0.4 MPa, the micro-vibration is dominated by a pair of adjacent large-scale vortices with low frequencies in the recess. However, when Ps = 0.5 and 0.6 MPa, the convection and shearing processes near the orifice outlet and the rectangular recess inlet become intense, resulting in the displacement of large-scale vortices. Eventually, the small-scale high-frequency pressure fluctuation structures have been also observed, which are closely related to the convection process within recess. With the increase in gas supply pressure, the high-frequency pressure fluctuations at the circular recess outlet gradually diminish, while those at the orifice outlet emerge and gradually enlarge. Meanwhile, the mode dominant frequency is transferred from around 200 kHz to around 1000 kHz. The energy fraction of the high-frequency pressure fluctuations is also greatly increased. [ABSTRACT FROM AUTHOR]

The RBCC (rocket-based combined-cycle) engine integrates a rocket engine into the flow passage of the ramjet engine, thereby significantly broadening the operating range and becoming one of the potential solutions for the reusable space transportations. The embedded rocket, as one of the core components of an RBCC engine, is strongly coupled to other components, such as the inlet and combustor, and can induce significant impacts on the inlet start behaviors. For the stable operation of the RBCC inlet, the start/unstart hysteresis characteristics and the reliable start boundaries driven by embedded rocket are experimentally and numerically studied. The results show that due to the function of embedded rocket jet, the inlet start/unstart hysteresis range of Mach number rises from Mach 1.79–1.87 to 1.85–1.90, and the back pressure hysteresis range changes from Pc/P∞ of 3.9–5.8 to 4.7–5.8. Meanwhile, during the increasing and decreasing process of the embedded rocket pressure, the inlet undergoes a transition between start and unstart, accompanied by hysteresis phenomena as well. Furthermore, three different control strategies are proposed for the start of RBCC inlet. Similar to the traditional ramjet inlets, the RBCC inlet can self-/re-start by reducing the back pressure. Particularly, owing to the synergistic effect of embedded rocket jet and back pressure, the RBCC inlet can self-/re-start by reducing the embedded rocket pressure from Procket/P∞ = 58 to 39 in the "embedded rocket dominated" cases, while the inlet self-/re-start can be achieved by increasing the rocket pressure from Procket/P∞ = 20 to 39 in the "back pressure dominated" cases. [ABSTRACT FROM AUTHOR]

Cavitation in tubes is a common occurrence in nature and engineering applications. Previous studies of cavitation bubble dynamics mainly consider bubbles in stagnant-water tubes, but the dynamics of cavitation bubbles in tubes with flow is not clear. This study investigates the dynamics of cavitation bubbles in tubes with flow by numerical simulations. The results show that, unlike bubbles in stagnant-water tubes, bubbles under the combined effects of water inflow and tube wall confinement exhibit asymmetric behavior along the axis of the tube. The inflow suppresses the development of the bubble interface near the tube inlet, causing that side of the interface to move with the inflow. In contrast, the expansion and contraction of the bubble and the generation of liquid jets occur on the side near the outlet. This feature results in significant asymmetry in the bubble interface; therefore, we introduce a skewness parameter to characterize the difference in length between the left and right parts of the bubble during the bubble evolution. The evolution of the bubble significantly affects the mass flow rate at the outlet of the tube, and even leads to backflow during the bubble contraction process. [ABSTRACT FROM AUTHOR]

For electric vehicle (EV) charging in North America, three AC connectors are standardized, resulting in a proliferation of charging stations which can only charge one of the three types of EV. We propose a "Universal EV Outlet" that works with an EV "carry along" charging cable—one end of the cable has a connector specific to that user's EV, the other a plug for the Universal EV Outlet. This proposal does not interfere with, nor require change to, any existing charging stations. It does not require any new types of inlets on EVs. The components are already standardized. Eight use cases are examined to illustrate the advantages, and some limitations, of the Universal EV Outlet. The use cases illustrate how this solution: resolves the problem of multiple AC charging connectors, makes today's "EV Ready" building codes more adaptable, lowers capital and maintenance costs, creates a solution to curbside and urban charging, increases energy efficiency, enables higher power three-phase AC charging for heavy vehicles, and facilitates use of EVs for building backup power and for vehicle-to-grid. Finally, we propose a standards-based active cable used with the Universal EV Outlet, which would allow fast and secure EV identification for curbside or other shared charging locations, usable today without modifications to current EVs. [ABSTRACT FROM AUTHOR]

AbstractThis article studies the effects of multi-field coupling on the S-duct by a self-developed fluid-solid-thermal bi-directional coupling code. The flow field inside the S-duct is complex with various vortices as the airflow turns. The results indicate that the total pressure recovery coefficient and the total pressure distortion index (DI) change rapidly at the beginning and reach a steady state at about 100s. The σ decreases by 12%, and the DI increases by 2% compared to the starting point. Structural deformation, size of separation zone, and wall temperature changes over time, and stabilizes around 100 s. The deformation mainly occurs at the outlet, with a maximum displacement of 3.65 mm for up-warping and 4.60 mm for expansion. The values of the total pressure recovery coefficient with S-ducts of bias distance with 20, 40, and 60 mm drop by 2.5%, 8.6%, and 12.1%, and the values of the total pressure distortion index increases with S-ducts of bias distance with 20, 40, and 60 mm increase by 10.8%, 15.1%, and 1.7%. The S-duct with a larger aspect ratio has larger separation zones and a smaller total pressure recovery coefficient. [ABSTRACT FROM AUTHOR]

Small Modular Reactors (SMRs) are an innovative option for power generation. This type of reactor offers numerous benefits and uses. The implementation of Fully Ceramic Microencapsulated fuel (FCM) in an integral pressurized water reactor (iPWR) with SMR characteristics has been studied previously. FCM has excellent thermal and irradiation resistance properties and is composed of a SiC matrix with dispersed TRISO fuel particles. To perform the thermo-hydraulic analysis of the core of an SMR using FCM as fuel, a computational model was built using CFD codes. The model describes a typical fuel assembly of the reactor and the main thermo-hydraulic parameters are calculated for the increased power values of 65, 80, and 100 MWt. To improve the thermo-hydraulic behavior of the core, it was considered to vary the values of mass flow, core inlet temperature, and system pressure. [ABSTRACT FROM AUTHOR]

Estimating singular pressure losses for multi-stage obstacles in pressurized hydraulic ducts is a challenging task. An experimental study was conducted in a closed-loop hydrodynamic tunnel to characterize the pressure losses of a system consisting of a porous fibrous foam placed in front of a bar rack. The pressure losses of different foam–rack configurations were measured over a range of inlet velocities in order to highlight the mutual influence of their characteristics on the flow. The interdependence between the two stages has been evidenced by both the experimental results and additional numerical simulations using RANS (Reynolds-Averaged Navier–Stokes Equations) simulations with a k- ω SST turbulent closure model. The pressure losses were first modeled using two approaches based on the assumption of either independence or full dependence between the stages. The respective advantages and limitations of these approaches led to an improved analytical formula that considers the transition of the flow from the porous foam to the bar rack. By taking into account an empirical transition factor, the proposed model improves the head loss prediction for all tested configurations, with an average relative error between the formula and experimental results less than that of the two simpler approaches. This study improves our understanding of global pressure losses in multi-stage systems that include a porous foam or other filtering or clogging media in front of bar racks. [ABSTRACT FROM AUTHOR]

[Display omitted] As lyophilization continues to be a critical step in the manufacturing of sensitive biopharmaceuticals, challenges often arise during the scale up to commercial scale or the transfer from one manufacturing site to another. While data from the small-scale development of the lyophilization cycle is abundant it is typically much more difficult to extract important information from commercial scale cycles, due to the lack of process analytical technologies available on the commercial line. There is often a reluctance to include wireless temperature or pressure probes during GMP operations due to the additional contamination risk, and retrofitting equipment such as the TDLAS can be prohibitively expensive. Further, as products become more advanced, the cost of consuming the product or even the availability of material may limit the opportunities to run commercial scale trials. This paper presents two novel methods to garner critical cycle information to allow for the evaluation of cycle performance without the need for expensive analytical equipment, costly revalidation and line downtime. Critically, this can be achieved using commonly available temperature and capacitance probes on existing commercial scale equipment. The first method is a calorimetric method, based on quantifying the differences in heat transfer liquid temperature between the shelf inlet and shelf outlet. This change in temperature results from the on-going sublimation, an endo-thermic reaction occurring during lyophilization. The second method uses the differential pressure between the chamber and condenser resulting from the vapor flow from vial to condenser during primary drying. As stated by the authors both methods align well and provide valuable cycle characterization data. [ABSTRACT FROM AUTHOR]