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This research work aims to theoretically examine the influence of various factors on the three-dimensional nanofluid flow. The study includes parameters such as temperature ratio coefficient, Prandtl numbers, Schmidt, Soret, Dufour, Biot, expansion ratio coefficient, Power index, and nanoparticle volume fraction parameter, as well as the effect of non-linear thermal radiation and magnetic parameter on the behavior of the nanofluid. These characteristics significantly impact the flow of the three-dimensional boundary layer in the presence of an expansion plate. To facilitate the investigation, we have selected nanofluids that contain water-based copper and aluminum oxide for this study. We have developed a model of a system of partial differential equations (SYS-PDEs) with non-linear terms. Based on selected similarity equations, the SYS-PDEs with non-linear terms has been transformed into a system of ordinary differential equations (SYS-ODEs) whose terms are non-linear. To approximate and solve the obtained SYS-ODEs, we utilized a modified spectral Chebyshev polynomials' first derivative pseudo-Galerkin spectral method. Additionally, we conducted an error analysis discussion to ensure the credibility of our results. We presented our analysis in graphical form and provided comments on each figure along with the effects of the various parameters studied. Consequently, we concluded that the power low is an essential factor affecting the flow's behavior, such as the nanofluid's velocity, temperature, and concentration. [ABSTRACT FROM AUTHOR]

The present study examines numerically a three-dimensional (3D) laminar and stationary flow around an idealized metal foam cell shaped as an empty cube with cylindrical edges. The physical configuration adopted consists of an isolated cell placed inside a plane channel crossed by air as a working fluid. The numerical investigation is carried out using the dimensionless Navier-Stokes equations resolved by finite volume method. The flow configurations given for several Reynolds numbers are described entirely using 2D and 3D maps. The plane maps give streamlines at the side and top fiber planes: the vertical side of the cell is normal to the flow. In addition, the critical locations and zones characterizing the flow are also localized: the saddle points, separation nodes, attachment points, foci of the recirculation zones, and the attachment lines. For the Reynolds number in the range 75 ≤ Re ≤ 500, the results show that the topography of the streamlines at the vertical plane in the middle of the lateral fibers of the cell (z = 5.3Dp) is developed into arc-shaped vortex rollers in the gap. In the wake, two saddle points reveal the zones of influence of these spiral structures, formed by two vortices (Bt and Nw) and zones of upwash and downwash. At a high value of Re (Re = 500), the upwash weakens but does not disappear. Two recirculation bubbles are associated with the two saddles, in the gap and the wake of the upper fibers, parallel to the flow. At Re =500, the distribution flow loses its symmetry and displays matter transfer between the two recirculation. The displacement of the saddle point in the wake is 9.65 times that in the gap. No vortex shedding is observed in the wake of cell due to the nullity of the frequency shedding (f = 0).The results indicate also that decreasing the pore diameter favors recirculation inside the cell gap. These recirculation lengths (Lrz, Lry) located respectively in the wake of planes z = 5.3Dp and y = Dp reduce the drag coefficient in equal proportion (51%) in the range 75 ≤ Re ≤ 500. It appears that the wake of the lateral fibers of the z=5.3Dp plane contributes better to the drag coefficient. We consider that the predominance of downwash associated with the instability of saddle point S.2 in the wake when Re increases leads to a decrease in the drag coefficient in the wake. [ABSTRACT FROM AUTHOR]

Stall, a complex flow phenomenon in centrifugal pump, plays a crucial role in pump safety and stability under part-load conditions. In this paper, a verified numerical simulation method is employed to analyze the three-dimensional flow field under the stall inception conditions. The results reveal the initial stall vortex occurs near the Q=0.7Qd condition in the prototype impeller. Based on stall formation mechanism, the high-velocity fluid near the blade pressure side is sucked into suction side of next impeller channel by setting a groove near the blade leading edge. This jet flow can prevent the narrow vortices near the impeller shroud from moving towards the blade suction side, thereby suppressing the formation of stall vortex. By comparing the effects of different groove locations, directions, and sizes on stall vortex control, the optimal groove width is determined to be approximately 1mm. Compared with the prototype impeller, the grooved impeller can completely eliminate the stall vortex and significantly reduce pressure pulsation under part-load conditions. Moreover, the head of grooved impeller is increased by nearly 15% under Q=0.6Qd condition, and the potential suppression mechanism is also explained. Based on the stall formation mechanism, this paper puts forward an effective stall control method, which delays the stall inception significantly. [ABSTRACT FROM AUTHOR]

In this work, to comprehensively analyze the flow field characteristics of a normal slot plasma synthetic jet actuator, three-dimensional simulation models are established for both normal slot and normal orifice actuators. A detailed comparative analysis of the three-dimensional flow field characteristics of these two actuators is performed. The results indicate that the motion shockwaves and jets generated by the normal slot actuator cover a larger and more uniform region, showing planar characteristics and excellent flow control uniformity. The total pressure ratio for the normal slot actuator is 3.59, significantly higher than the value of 3.50 for the normal orifice actuator, indicating lower pressure loss in the former. Additionally, the normal slot has a larger average exit Mach number (Ma), indicating a stronger flow control capability. It also achieves the peak Ma in a shorter time, indicating a faster momentum output response. Therefore, compared with the normal orifice actuator, the normal slot actuator has better potential for flow control. [ABSTRACT FROM AUTHOR]

Today, due to advances in computing power, Reynolds Averaged Navier-Stokes (RANS) solvers are widely preferred for quasi-three-dimensional (Q3D) blade-to-blade analysis. This study investigates the performance of different flux calculation methods and turbulence models with a density-based RANS solver (Numeca®) in blade-to-blade analysis. A block-structured mesh topology is used to create a solution grid around the airfoil. Spatial discretization is performed in the pitchwise direction to represent the quasi three-dimensional flow, while only one computational cell is used in the radial direction to simulate the flow through the Q3D cascade. The computational grid around the airfoil is created with the Autogrid® tool using the block mesh topology. For the convective flow calculations, both the central and upwind methods available in Numeca® are applied separately. The Baldwin Lomax (BL), Spalart Allmaras (SA), Shear Stress Transport (SST), Explicit Algebraic Reynolds Stress Model (EARSM) and k-e (KEPS) turbulence models are used for the turbulent shear stress calculations. In order to evaluate the aerodynamic performance of the spatial discretization methods and turbulence models, the isentropic Mach distribution on the airfoil surface, the total pressure loss and the exit flow angle behind the blade are compared with the experimental data of six test cases. In the compressor cases, the Spalart-Allmaras turbulence model with the Central scheme gives the best results in terms of average loss prediction, while no turbulence model is superior to the other in terms of exit angle prediction. On the turbine side, EARSM and KEPS give better performance in terms of loss prediction for the low Reynolds case compared to others, while the Spalart-Allmaras turbulence model is better for the high Reynolds cases. [ABSTRACT FROM AUTHOR]

• The flow characteristics of vertical slot fishways at different slopes (1.5%, 3.0%, 4.5%, 6.0%) were systematically studied. • The turbulence and energy dissipation in a fishway increase with increasing slope. • The distribution of vorticity shows little variability with increasing slope but may interfere with the passage of fish through the vertical slot. • An increase in water depth has no significant effect on the flow characteristics in the pool. The effects of a vertical slot fishway slope (with slope values from 1.5% to 6%) on a flow field are numerically investigated, using a re-normalization group k – ε model. The distribution of the velocity, turbulence kinetic energy (TKE), average energy dissipation rate per unit volume (E), and vorticity for different slopes are systemically explored. The results indicate that, with an increase in slope, the appearance of downward flow in conjunction with an increase in vertical velocity results in three-dimensional flow characteristics. The recirculation region in H s , at a 6.0% slope, was 20.9% less than that at a 1.5% slope. Meanwhile, the flow velocity in the vertical slot region grew with increasing slope, which would limit the passage of fish with burst speed lower than the velocity in the vertical slot region. The TKE and E may locally exceed the threshold at larger slopes. Furthermore, vorticity distribution shows little variability with increasing slope, but may interfere with the equilibrium of the fish in the vertical slot region. In addition, the change in water level has little effect on the flow field, which is changed by the increase in slope. These findings can aid vertical slot fishway designs especially in terms of the efficiency of fish passage. [ABSTRACT FROM AUTHOR]

Temporal flow characteristics of a 3D centrifugal impeller suction system were numerically studied in vacuum conditions. The blockage of the high-speed rotating impeller appeared, which greatly dropped the suction of the layer suction device. The temporal flow characteristics of the 3D centrifugal impeller suction system were worthy of attention in vacuum conditions. Separation vortices were generated near the blade suction surface. The blocking mechanism of the passage was further analyzed at different extremely low flow rates through the time-space evolution of the streamline. The Q-criteria was introduced to analyze the vortex evolution within the fluid domain of the impeller. Vortex evolution law was captured--the vortices always generated near the suction surface of the blade and moved to the pressure surface of the adjacent blade in the same passage and disappeared. The uniform distribution of three stall cells was captured through the diagram of turbulent kinetic energy. The flow rate increased, and the vortex evolution period gradually decreased. The comparison of pressure fluctuations in different conditions further demonstrated the flow mechanism at the vacuum flow rate was different from that at low flow rates. The sharp increase of pressure fluctuations near the blade pressure surface was consistent with the phenomenon near the suction surface. The pressure fluctuation at extremely low flow was mainly composed of scattered fluctuations caused by fluid separation. The steady and unsteady characteristics described the internal flow characteristics of this suction system at vacuum-flow rates. Theresults provide a profound design for vacuum cleaners. [ABSTRACT FROM AUTHOR]

The main purpose current exploration is to examine the influence of viscous dissipation and nonlinear radiation in three-dimensional (3D) Williamson fluid flow on an exponentially stretching through porous medium with the effect of activation energy along with chemical reaction. By employing suitable transformation, the nonlinear partial equations (PDEs) are transmuted to nonlinear ordinary differential equations (ODEs) which are subsequently solved numerically by using Range-Kutta method with shooting technique by utilization Matlab script. Characteristics of resulting physical parameters appearing in modeling like the Weissenberg number, Prandtl number, nonlinear radiation parameter, porosity parameter, Eckert number and chemical reaction parameter are comprehensively analyzed in graphical forms with an interest in providing the physical meaning to each parameter. The outcomes anticipate that, the thermal profile is improved by the increase in the values of nonlinear radiation parameter due to inner heat. The thermal profile enhances by strengthening of Eckert number but it has opposite trend through Prandtl number. The impact of obtained parameters on skin friction coefficient, mass and heat transfer rates is illustrated by tables. The validity of the present findings is presented by comparing them with the previous investigations. [ABSTRACT FROM AUTHOR]

A numerical study was carried out on dual solutions of rotating stretching/shrinking surfaces to explore the influence of convective boundary conditions, viscous dissipation, thermal radiation, and heat sources/sinks on 3-D hybrid nanofluid flow. Hybrid nanofluids have great potential for a variety of applications due to their unique properties and versatility. It is improved the effectiveness of heat transfer rates. The main objective of this study is to investigate the influence that certain parameters on the temperature and velocities profiles against the parameters, including the volume fraction of copper, suction effect, viscous dissipation, thermal radiation, Biot number and rotating parameter. Further, the impact of the suction effect and shrinking sheet on reduced heat transfer and skin friction is also considered against the volume fraction of copper. The nonlinear partial differential equations are transformed into a collection of ordinary differential equations by including linear similarity variables. The generated combination of higher order nonlinear ODEs is solved via a boundary value algorithm called bvp4c, which executes on the MATLAB computing tool. The findings confirmed the existence of two branches (dual solution) with varied quantities of copper volume fraction according to the shrinking surface and suction effect. Additionally, as the Biot number, Eckert number, thermal radiation, and copper volume fraction all increase in strength, the rate at which heat flows in both solutions also increases. However, the heat transfer rate declined as increased the suction effect. Besides, when a positive and negative increment is applied to the rotational parameter, both solutions suffer an increase in both velocities. In summary, unique solutions are obtained S < S ci for suction effect and λ < λ ci for the shrinking region. The outcomes came to the conclusion that hybrid nanofluid has a faster rate of transferring heat than standard nanofluid offers. [ABSTRACT FROM AUTHOR]

Flow control methods have been gradually applied to improve the flow field characteristics of axial compressors. However, most of the current research is focused on the cascade, and few studies have taken a compressor as the research object. Therefore, a 3.5-stage transonic axial compressor is adopted to explore the characteristics of different flow control schemes. The effects of the micro-vortex generator (MVG), segmented boundary layer suction (BLS), and combined technology (COM) on the MVG and BLS are compared by the numerical simulation method. The research results are summarized as follows. The excessive accumulated low energy fluid in the blade passage induces the occurrence of a corner stall in the last stage stator of an axial compressor. At this time, the compressor can still work, but the performance has accelerated deterioration. The flow characteristics are effectively improved when the MVG is introduced, the stall margin improvement ΔSM and the peak efficiency improvement Δηe of the last stage are 2.1% and 1.02%, respectively. Moreover, the BLS shows advantages in removing the three-dimensional reverse flow and decreasing the total pressure loss compared with the MVG, the ΔSM of the last stage is 2.69%, and the Δηe is 1.83%. When the combined technology is applied, it shows a significant advantage in delaying the occurrence of a corner stall, and the stall margin of the last stage is improved by 2.71%. Based on a quantitative analysis method using loss sources, the three flow control schemes show significant advantages in reducing the secondary flow loss sources and the wake loss sources. Above all, the BLS shows significant advantages in reducing the total pressure loss, and the COM shows an advantage in expanding the stable operating range. The research results will provide a reference for studies of flow control methods related to reducing flow losses and widening stability margins. [ABSTRACT FROM AUTHOR]

The three-dimensional flow of non-Newtonian fluid over slendering stretching sheet is taken into account. The effects of a radiative and chemical reaction using the heat source/sink non uniformly considered in the present model. The Buongiorno model is applied to the fluid flow region. The heat and mass transfer phenomena have been applied to analyze the influence of heat generation. The governing model has been developed using the flow assumptions such as boundary layer approximations in terms of partial differential equations. The differential equations become dimensionless after implementing the transformations. The dimensionless system is further solved through a numerical scheme using the Matlab Software packages. The results of physical factors are deliberated through graphs as well as tables. The temperature curves improved due to higher values of heat generation. The heat generation improved due to the kinetic energy increase as well as the movement of particles enhanced due to the temperature increase. Curves of the temperature improved due to higher values of radiation. When the radiation falls on the fluid surface, it improved the temperature of the liquid because hot particles strike the cool particles of fluid which improved the temperature of the liquid. [ABSTRACT FROM AUTHOR]

• Estimate pressure oscillation places and its magnitude for different cases with time. • Explaining the phenomena with the reasons leading to pressure oscillation in details. • Parametric study to introduce the optimized dimensions for enhancing the performance of deflector jet servo-valve. The performance of deflector jet servo-valve is highly affected by the flow field characteristics in the pilot stage of the deflector jet servo-valve. This research used the large eddy simulation method to study the pressure pulsation characteristics of the front stage flow field of DJSV, which has a high significance for the reasonable design of DJSV and the suppression of self-excited oscillation. The geometric model of the three-dimensional flow field of the jet pilot stage of the servo valve deflection plate was established. LES method was used to analyze the influence of the geometric parameters of the jet outlet, amplifier and receiving port on the flow field distribution characteristics of the pre-stage. The results show that pressure oscillation is highly affected by the inlet pressure. Structure optimization is a good solution for decreasing pressure oscillation in deflector jet servo valve. [ABSTRACT FROM AUTHOR]

This study investigates Thomas’ cyclically symmetric attractor dynamics with mathematical and electronic simulations using a proportional fractional derivative to comprehend the dynamics of a given chaotic system. The three-dimensional chaotic flow was examined in detail with Riemann-Liouville derivative for different values of the fractional index to highlight the sensitivity of chaotic systems with initial conditions. Thus, the dynamics of the fractional index system were investigated with Eigenvalues, Kaplan–Yorke dimension, Lyapunov exponent, and NIST testing, and their corresponding trajectories were visualized with phase portraits, 2D density plot, and Poincaré maps. After obtaining the results, we found that the integer index dynamics are more complex than the fractional index dynamics. Furthermore, the chaotic system circuit is simulated with operational amplifiers for different fractional indices to generate analog signals of the symmetric attractor, making it an important aspect of engineering. The qualitative application of our nonlinear chaotic system is then applied to encrypt different data types such as voice, image, and video, to ensure that the developed nonlinear chaotic system can widely applied in the field of cyber security. [ABSTRACT FROM AUTHOR]

The current study concentrated on the analysis of entropy generation in three dimensional mixed convection flow of couple stress nanofluid under the effect of high order velocity slip flow, passive and active control conditions. The problem advances more significance with the effect of non-Fourier's heat, and non-Fick's mass flux model to scrutinize the heat and mass transport rate. The high-order partial differential equations obtained from the designed problem are transmuted into higher order ordinary differential equations using similarity conversion and lastly solved by using bvp4c. Through this investigation how governing parameters have affected the flow problem were examined and offered in graphical and tabular form. It is discovered that the occurrence of couple stress inflow problem upsurges the velocity of the fluid and on the other hand it causes a reduction in the entropy production. Likewise, it is detected that temperature improves by snowballing the Hartman parameter. Moreover, the temperature and concentration disseminations are greater all for the situation of an active control while correlated with a case of passive control. Also, the same is true for numerical results of Nusselt number and Sherwood number that is due to an active control is greater than all for the case of passive control. Furthermore, this theoretical and numerical deliberation bears the potential to beneficial in the field of bio-fluid dynamics. [ABSTRACT FROM AUTHOR]

In the present work, the effects of modifying the tongue geometry of a centrifugal pump on pressure pulsations under the design and off-design conditions are carried out numerically by the unsteady analysis of fluid flow. Numerical modeling based on the Re-Normalization Group (RNG) k-e turbulence model using a Mosaic mesh structure, a technology which can easily, quickly and formally connects any type of mesh for complex geometries and flow regimes, is applied to simulate the flow within the modeled pump, which is validated with the available experimental results. The flow is simulated through a commercial Computational Fluid Dynamics (CFD) software that solved Reynolds-Averaged Navier-Stokes (RANS) equations for a three-dimensional unsteady flow. In addition to choosing Qd (the design flow rate), 0.4Qd and 1.2Qd are also taken into account as the inlet flow rates. Besides, pressures of 101KPa and 13KPa are considered as additional inlet conditions for this investigation. This unsteady simulation employing different inlet conditions is used to investigate the impacts of various volute tongue angles on the pressure coefficient (cp). Results indicate that, overall, by changing the angle from 40° to 85°, the value of the pressure coefficient at the pump outlet grows by about 10% where it also causes a rise in the amplitude of pressure fluctuations. By the same token, a decrement to the inlet flow rate up to 40% of the nominal value brings about the amplitude of pressure fluctuations at the pump outlet to be increased significantly. [ABSTRACT FROM AUTHOR]

We perform a thorough numerical analysis of the impact of inflow conditions on the aerodynamic performance of a tandem cascade. In particular, we investigate the effects of the incidence angle and the inlet boundary layer (IBL) thickness on the three-dimensional flow field structure and aerodynamic performance. Our results show that the gap flow strength of the tandem cascade decreases with the increase of incidence angle, and it can effectively reduce the mixing of the wakes of the forward blade (FB) and rear blade (RB). In turn, this prevents the passage vortex (PV) in the RB passage from developing along the circumferential direction. The occurrence of IBL does not modify the effects of the incidence angle on the tandem cascade, however, it reduces the load of the RB and the gap flow strength near the endwall. Under all incidence angles, IBL increases the total pressure loss of the tandem cascade, and decreases the static pressure rise (except for an incidence angle equal to -6°). The maximum loss increment is at 2° incidence angle, and the maximum static pressure rise decrement is at 6° incidence angle (Thick-IBL condition) or 7° incidence angle (Thin-IBL condition). Furthermore, we found that the presence of IBL changes the minimum loss condition from 0° (design condition) to -2° incidence angle. Our results thus indicate that in the practical engineering application of the tandem cascade, the reality that IBL degrades the tandem cascade performance in the full incidence angle range should be considered. And the strong endwall secondary flow effect caused by IBL should be considered in the tandem cascade threedimensional design, so that the tandem cascade two-dimensional performance advantage can be better played. [ABSTRACT FROM AUTHOR]

Two-dimensional instead of three-dimensional computational fluid dynamic solutions of flow problems are quite often used in industry to facilitate short design turn-around times with varying degrees of success. A simple and robust approach for improving the accuracy of two-dimensional computational fluid dynamics solutions for problems involving internal flow passages in industrial applications is presented. The technique utilizes an approximation to the shearing stresses that act in the fully three-dimensional case but are ignored in the traditional two-dimensional approximation. Although the technique does not fully account for all the three-dimensional effects in such flows, it gives a reasonable estimate of the operation of devices with internal flows, even those involving transients. The usefulness and accuracy of the method are demonstrated through the application of the method to predict the performance of a supersonic fluidic oscillator for industrial design purposes. This brief provides industrial designers with a simple and robust tool for improving the accuracy of their computational fluid dynamic simulations. [ABSTRACT FROM AUTHOR]

Sewage pumps are one of the most popular types of fluid machinery in municipal, industrial, and environmental engineering and many other fields. The influence of tip clearance size on the pump performance and internal flow field distribution within a sewage pump was investigated in this study based on numerical calculation and test verification. Three models with different tip clearances were obtained by adjusting the assembly structure and simulated by the computational fluid dynamics software to solve the Navier-Stokes equations for three-dimensional steady flow. The accuracy of numerical methods was verified by comparison with the experimental results. The sewage pump performance under different tip clearances was then compared and analyzed. The structure and propagation of the vortices inside the impeller caused by the leakage flow with different tip gaps were also analyzed. The leakage flow in the impeller couples with the cover reflection and secondary flows, forming different vortex structures in various locations of the impeller channel. These vortex structures cause large hydraulic losses near the blade suction surfaces. This finding could provide useful insights for the improvement of the hydraulic performance and operational stability of semi-open sewage pumps. [ABSTRACT FROM AUTHOR]

The utilization of Riverbank Filtration Systems (RBF) presents a promising approach for obtaining potable water from rivers or streams. However, the effectiveness of this technique relies significantly on two key factors: the width of the river and the presence of a clogging layer beneath the streambed, both of which influence the degree of contamination in the extracted water. Prior studies have predominantly relied on numerical models or simplistic one-dimensional flow assumptions to address these variables. In contrast, this research introduces a 3D analytical model utilizing the Green's function approach to analyze the movement of contaminants from the river towards the extraction well within RBF systems. By accounting for the dynamic interaction between river width and the clogging layer, this model offers a more accurate depiction of contaminant transport in three-dimensional water flow scenarios. The accompanying MATLAB code facilitates numerical integration of model equations, producing graphical representations for various hydrological inputs. Validation against MODFLOW software demonstrates a remarkable agreement, with outcomes aligning at 98–99%. Key findings underscore the exacerbation of pollutant concentrations with heightened clogging, increased river width, and optimal well placement. Moreover, the analysis underscores better predictive accuracy achieved by incorporating actual river width values compared to simple linear approximations. Notably, the research reveals minimal impact on contaminant concentrations when the distance between the river and the well exceeds twice the river's width, offering valuable insights for system design and management. [ABSTRACT FROM AUTHOR]

This study evaluates how Reynolds-averaged Navier-Stokes (RANS) models perform in simulating the characteristics of mean three-dimensional perturbed flows in pipes with targeted wall-shapes. The principal objective of this investigation is to evaluate which of the well-established RANS models can best predict the flow response and recovery characteristics in perturbed pipes at moderate and high Reynolds numbers (1×104-1.58×105). First, the flow profiles at various axial locations are compared between simulations and experiments. This is followed by assessing the well-known mean pipeflow scaling relation in the far downstream region, where the flow obtains a fully-developed state. The consistency of computationally predicted results and their similarities with experiments suggested that the Standard k-ε model can accurately capture the pipeflow characteristics in response to introduced perturbation with smooth sinusoidal axial variations. [ABSTRACT FROM AUTHOR]

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Unsteady three-dimensional flow simulations on a twin-screw pump are performed for an assessment of the radial, circumferential, and flank gap flow effect on the pump performance. By means of the overset grid technique, rigid computational grids around the counter-rotating spindles yield a high cell quality and a high spatial resolution of the gap backflow down to the viscous sublayer in terms of y+<1⁠. An optimization of the hole-cutting process is performed on a generic gap flow and transferred to the complex moving gaps in the pump. Grid independence is ensured, and conservation properties of the overset grid interpolation technique are assessed. Simulation results are validated against measured pump characteristics. Pump performance in terms of pressure build-up along the flow path through the spindles and volume flow rate is presented for a wide range of spindle speed and pump head. Flow rate fluctuations are found to depend on head but hardly on speed. By a profound assessment of the respective radial, circumferential, and flank gap contribution to the total backflow, the importance of the most complex flank gap is pointed out. Backflow rate characteristics in dependence on the pump head and the pump speed are presented. [ABSTRACT FROM AUTHOR]

An experimental study on the effect of sidewalls on the flow characteristics of a three-dimensional turbulent square wall jet is carried out at a Reynolds number of 25,000. The sidewalls are defined as the two parallel plates along the vertical jet centerline. Four different sizes of sidewall enclosure (here after referred to as 'SWE') are placed at the lateral positions (z) of ±3.5h, ±4h,±4.5h, and ±5h from the vertical jet centerline plane, where h is the height of square jet. The mean characteristics of fluid flow in wall normal (y) and lateral (z) directions at different downstream locations (x/h=0.2-45) are measured using a hotwire anemometer. The velocity measurements are also performed in the z - y lateral plane at four downstream locations (x/h=30,35,40, and 45). Results indicate that the mean velocity profile in lateral and wall normal directions behaves differently depending on the size of SWEs. The decay rate of the maximum mean velocity increases with decrease in size of SWEs after the downstream location (x/h=20). The decay rate of the maximum mean velocity increases about 5.6% in 140 mm SWE as compared to 200 mm SWE. It is noted that spread of the jet in wall normal and lateral directions increases with decrease in size of SWEs after the attachment of the flow stream on the sidewalls. In the far-field location of the present case, the smaller size of SWE (140 mm SWE) has 10.7% and 23.1% higher spread rate as compared to larger size of SWE (200 mm SWE) in wall-normal and lateral directions, respectively. It is also seen that the self-similar profile gets delayed in wall-normal direction as compared to lateral direction for all the cases. The wall-normal self-similar profile is obtained early with increase in the size of SWEs and it is obtained at x/h=30, 27, 24, and 20 for 140 mm, 160 mm, 180 mm, and 200 mm SWEs, respectively. The flow stream seems to climb the sidewall and this tendency increases with increase in size of SWEs. [ABSTRACT FROM AUTHOR]

Infrastructure, including roads, bridges, and municipal facilities, act as barriers to the downstream propagation of flood waves following a dam failure. The aim of this work is to investigate the effects of the obstacles and their arrangement on the evolution of flood waves during a dam breach using a numerical approach. The obstacles were arranged in two arrangements (triangular and inverted triangular) perpendicular to the flow direction in the downstream channel. Wave propagation during dam failure and flow dynamics were modelled by the finite volume method (FVM) using a CFD package. The evolution of the free surface of the dam breach was traced using the volume of fluid (VOF) method. However, the uncertainty of the model was evaluated using a sensitivity analysis with respect to the mesh resolution and turbulence models. The turbulence characteristics were captured by large-eddy simulations (LES) after validating the model using experimental data from the literature. The results show that the model can efficiently reproduce the wave development during a dam failure and the flow characteristics. The arrangement of the obstructions played an important role in the development of flow around the obstructions through the downstream channel. In this direction, the transitional flow regime, resultant forces in reservoir, and three-dimensional flow velocity around the obstaclees were predicted for different arrangements. [ABSTRACT FROM AUTHOR]

Reynolds-averaged Navier–Stokes (RANS) approach is used to simulate the steady-state of a family of pressure-induced turbulent separation bubbles in the presence of sidewalls. Different turbulence models are employed with a specific emphasis on the baseline explicit algebraic Reynolds stress model (BSL-EARSM) and the simulations are compared with experimental data. The separation and reattachment of a flat-plate turbulent boundary layer are generated through a combination of adverse and favorable pressure gradients (APG-FPG) by numerically reproducing the geometry of the wind-tunnel test section used for the experiments. Three cases are considered a large (LB) and a medium (MB) bubble presenting mean backflow, and a small bubble (SB) without mean-flow reversal. This is achieved by varying the streamwise position of the APG/FPG transition. Good agreement between the BSL-EARSM-computed solutions and the experimental results are obtained for wall-pressure and skin-friction distributions on the centerline plane of the test section as well as for the overall three-dimensional flow topology. However, both detachment and reattachment are predicted too early and the bubble length is slightly overestimated for cases LB and MB. For case LB, the streamwise Reynolds stress is estimated fairly well but its production is somewhat delayed. Normal and shear stresses are in good agreement with the experiments in the upstream part of the bubble but are significantly over-estimated in the reattachment region. The k−ω shear-stress transport (SST) model with the so-called reattachment modification performs better than the other tested linear-eddy-viscosity models but it is still unable to reproduce accurately the three-dimensional flow topology even for the “simplest” case SB. Overall, the results suggest that BSL-EARSM is the most suitable turbulence model for this flow configuration. [ABSTRACT FROM AUTHOR]

This study presents a two and three-dimensional numerical simulations of a flow-through a sudden expansion and contraction microchannels. The finite element method was used to discretize the equations governing the physical model. By carrying out the numerical simulations, results indicate the apparition of a separate vortex, situated in the corner after the sudden expansion of the microchannel for low Reynolds numbers. For high values of Reynolds number and expansion ratios, the vortex separation length increases. Also, the three-dimensional character of the flow is more pronounced for higher Reynolds numbers. [ABSTRACT FROM AUTHOR]

Fluid loading within an intracranial aneurysm is difficult to measure but can be related to the shape of the flow passage. The outcome of excessive loading is a fatal hemorrhage, making it necessary for early diagnosis. However, arterial diseases are asymptomatic and clinical assessment is a challenge. A realistic approach to examining the severity of wall loading is from the morphology of the aneurysm itself. Accordingly, this study compares pulsatile flow (Reynolds number Re=426, Womersley number Wo=4.7) in three different intracranial aneurysm geometries. Specifically, the spatio-temporal movement of vortices is followed in high aspect ratio aneurysm models whose domes are inclined along with angles of 0, 45, and 90deg relative to the plane of the parent artery. The study is based on finite volume simulation of unsteady three-dimensional flow while a limited set of particle image velocimetry experiments have been carried out. Within a pulsatile cycle, an increase in inclination (0-90 deg) is seen to shift the point of impingement from the distal end toward the aneurysmal apex. This change in flow pattern strengthens helicity, drifts vortex cores, enhances spatial displacement of the vortex, and generates skewed Dean's vortices on transverse planes. Patches of wall shear stress and wall pressure shift spatially from the distal end in models of low inclination (0-45 deg) and circumscribe the aneurysmal wall for an inclination angle of 90deg. Accordingly, it is concluded that high angles of inclination increase rupture risks while lower inclinations are comparatively safe. [ABSTRACT FROM AUTHOR]

The transport of pollutants in the large rivers especially in the lowest downstream reach of a river, in which the velocity and the intensity of flow turbulent become very low, is performed to a great extent by dispersion. Any measure to enhance the level of turbulence in the flow field will increase the mixing of pollutants. The main goal of the present study is to investigate how the transverse mixing is increased by using a triangular vane (TV). TV is a hydraulic structure used for bank protection and habitat restoration and is suitable for fish and other aquatic organisms. Experiments were carried out in a flume of 10m long and 0.8m wide. Two different conditions of with and no vane were tested under four different flow conditions. A salt solution was used as a tracer. An electronic concentration measuring equipment consisted of conductivity probes was used which can measure the concentration at 49 nodes in four cross-sections downstream simultaneously. The three-dimensional velocity components were also measured by using the electromagnetic velocity meter and the characteristics of three-dimensional flow patterns including turbulent kinetic energy (TKE) and the vertical distribution of the transverse velocity were analyzed. The result showed that the TV by deviating the velocity vectors to the transverse direction, by developing the secondary flows and by displacing the position of the rotating cells in different transverse sections, causes the transverse mixing to increase 3.2 times and to reduce the complete mixing length by as much as 76% compare to the case of no vane. The average values of the TKE found to be increased by as much as 3 times. Finally, a new dimensionless parameter has been proposed to correlate dimensionless transverse mixing to the flow parameters. [ABSTRACT FROM AUTHOR]

The impact of compressibility modified RANS turbulence closures is investigated for high subsonic round and chevron jet flows with Mach = 0.9 and Re = 1.03×106, including the predicted acoustic noise generation. The well-documented chevron jet flow and noise cases, namely NASA SMC000 and SMC006 are selected as the simulation configurations. Two compressibility RANS closures are considered, which are based on the k-ε turbulence model. The first type only considers the compressibility dissipation rate, and the second type accounts for three modifications of compressibility dissipation rate, pressure dilation and production limiter. The acoustic noise is calculated employing the SNGR (Stochastic Noise Generation and Radiation) method using the flow prediction of the three-dimensional RANS simulations. The results show that both of the two types of compressibility modified RANS models improve the accuracy of the mean flow and turbulence quantities. This results in more accurate jet noise predictions than with the standard RANS model. The first type modification is found to be moderate and the second type is remarkable. The noise results by the second type model, i.e. Sarkar2 model, agree with the experimental data quite well. For the mean flow field, the compressibility modified model (Sarkar2 model) estimates a shorter potential jet core, and improved predictions of the velocity in the downstream region are observed. The study demonstrates the importance of considering the compressibility modified RANS closure for the noise prediction of high-speed jets via the comparison to experimental data. Hence, the SNGR method is found to be cost effective for jet noise prediction, when compared to other approaches. [ABSTRACT FROM AUTHOR]

The application of the high-order accurate schemes with multi-block domains is essential in problems with complex geometries. Primarily, accurate block-interface treatment is found to be of significant importance for precisely capturing discontinuities in such complex configurations. In the current study, a conservative and accurate multi-block strategy is proposed and implemented for a high-order compact finite-difference solver. For numerical discretization, the Beam-Warming linearization scheme is used and further extended for three-dimensional problems. Moreover, the fourth-order compact finite-difference scheme is employed for spatial discretization. The capability of the high-order multi-block approach is then evaluated for the onedimensional flow inside a Shubin nozzle, two-dimensional flow over a circular bump, and three-dimensional flow around a NACA 0012 airfoil. The results showed a reasonable agreement with the available exact solutions and simulation results in the literature. Further, the proposed block-interface treatment performed quite well in capturing shock waves, even in situations that the location of the shock coincides with block interfaces. [ABSTRACT FROM AUTHOR]

The Buoyancy-driven flow of two immiscible liquids having varying density and viscosity is studied in a three- dimensional inclined confined channel. Initially, the heavier/lighter liquids occupy the upper/lower parts of the channel, respectively, which is an unstable configuration. The numerical simulations are performed using a multiphase lattice Boltzmann method (LBM) that is further implemented on the graphics processing unit (GPU). The three-dimensional flow dynamics and the associated physics are studied based on various parameters such as viscosity ratios (m), Atwood numbers (At) and Reynolds numbers (Re). The results were presented in the form of iso-surface/contour plots, average density profiles, and lengths of interpenetration. It is observed that larger interpenetration occurs with iso-viscous liquids having higher density gradients (higher At). The Reynolds number had a non-monotonic effect on the axial lengths of interpenetration (Lp*); Lp* increases till Re = 500 and then decreases for Re = 1000. At larger Re, due to the development of Kelvin- Helmholtz instabilities higher transverse interpenetration is observed. [ABSTRACT FROM AUTHOR]

The increasing demand for functional-integrated lightweight components is bringing established manufacturing technologies to their limits and motivates research into the innovative process class of sheet-bulk metal forming (SBMF). By applying bulk forming operations to sheet metal, thin-walled components with integrated functional elements can be produced in short process chains by a three dimensional material flow. Currently, pre-cut blanks are frequently used for this purpose. Manufacturing components from coil would combine the advantages of SBMF with those of production from coil regarding high output quantities. Therefore, the objective of the present research is to develop a fundamental process understanding for SBMF of parts from coil. For this purpose, a lateral and a backward extrusion process are set up and numerically mapped for a process analysis. Known challenges in SBMF of pre-cut blanks are a limited component accuracy due to a partly uncontrolled material flow and high tool loads. Consequently, both are addressed in context of a production from coil in a combined numerical-experimental approach. An anisotropic material flow is identified as a coil-specific challenge and fundamental difference to the SBMF of blanks. It causes an unequal forming of the components. The sheet geometry as well as a local pre-hardening induced by the forming of previous parts are found to determine the anisotropic material flow. In addition, an understanding of the effects of anisotropic material flow on tool loads is developed. An unequal deflection of tools is found as a tool-specific challenge. The obtained process knowledge provides a basis for research into measures to counteract the anisotropic material flow as a central challenge of SBMF of coils in future work. [ABSTRACT FROM AUTHOR]

This article concerns a class of time-optimal state constrained control problems with dynamics defined by an ordinary differential equation involving a three-dimensional steady flow vector field. The problem is solved by virtue of an indirect method based on the maximum principle in Gamkrelidze's form. The proposed computational method essentially uses a certain regularity condition imposed on the data of the problem. A regularity assumption guarantees the continuity of the measure multiplier associated with the state constraint and ensures the appropriate behavior of the corresponding numerical procedure which, in general, consists of computing the entire field of extremals for the problem in question. Several examples of vector fields are considered to illustrate the computational approach. [ABSTRACT FROM AUTHOR]

The limitation of energy resources in the world has cut the attention of many researchers to find new resources of clean energy and develop methods for recovering exergy losses. Twin screw expander (TSE) is one of the positive displacement machines that has been widely applied in recent years to recover mechanical power from fluids due to its lower installation, operation, and maintenance costs in comparison with common expansion turbines (CET). In this paper, technical and economic conditions of a city gate station (CGS) were studied with the aim of recovering exergy loss using a TSE. A computational fluid dynamic code was used to simulate the three-dimensional fluid flow in the TSE. The simulation results for Shahroud station —a CGS located in the east of Iran— revealed that, unlike CET, flow and pressure fluctuations in different seasons of the year did not put any restrictions on the use of TSE whereby 85.3% of annual loss exergy was recovered. Economic studies showed that the internal rate of return (IRR) and payback period of TSE utilization were obtained of 27.6% and 4.4 years, respectively, making the investment in CGS stations more practical compared to the CET. [ABSTRACT FROM AUTHOR]

The limitation of energy resources in the world has cut the attention of many researchers to find new resources of clean energy and develop methods for recovering exergy losses. Twin screw expander (TSE) is one of the positive displacement machines that has been widely applied in recent years to recover mechanical power from fluids due to its lower installation, operation, and maintenance costs in comparison with common expansion turbines (CET). In this paper, technical and economic conditions of a city gate station (CGS) were studied with the aim of recovering exergy loss using a TSE. A computational fluid dynamic code was used to simulate the three-dimensional fluid flow in the TSE. The simulation results for Shahroud station --a CGS located in the east of Iran-- revealed that, unlike CET, flow and pressure fluctuations in different seasons of the year did not put any restrictions on the use of TSE whereby 85.3% of annual loss exergy was recovered. Economic studies showed that the internal rate of return (IRR) and payback period of TSE utilization were obtained of 27.6% and 4.4 years, respectively, making the investment in CGS stations more practical compared to the CET. [ABSTRACT FROM AUTHOR]

• Positive surge translation in an asymmetrical canal is three-dimensional. • Detailed experiments performed in a 19 m long canal, with 1 V:5H transverse bed slope. • Geometry corresponded to a distorted scaling of natural channel with tidal bores. • Complicated transient secondary motion behind surge. • Leading edge of the surge arrived first in the shallow-water section. A positive surge is an unsteady open channel flow motion characterised by a sudden rise in water surface elevation. The literature is focused primarily on rectangular channels. Herein, the free-surface features of positive surges propagating upstream were investigated in an asymmetrical canal. The surge propagation was a three-dimensional unsteady flow motion, resulting in a complicated transient secondary motion compared to positive surge propagating in rectangular canals. The present results may be relevant to surge propagation in man-made trapezoidal canals and natural irregular-shaped channels. [ABSTRACT FROM AUTHOR]

• Gravel-bar vegetation survives large floods at the downstream edges of sand bars. • The shear force is weak at the downstream of the bar crest even in large floods. • The gravel bars with steep slope on the downstream edge develop on the inner bank of a sharp bend. • The maintenance of bars and the refugia at sharp bends preserves cobble-bar vegetation. In order to understand the mechanism of preserving cobble-bar vegetation, a vegetation dynamics field survey and numerical simulation of flood flows have been conducted. The study focuses on sparse perennial community established on cobble bars of a river in Japan. The field survey conducted over ten years reveals the existence of special spots where small number of individuals survive large floods providing refugia for the species. Three-dimensional simulation further identified that the locations of refugia correspond to the low bed-shear force area created by the complex three-dimensional flow downstream of cobble bars that develop on the inner side of sharp bends. The sudden steep drop downstream of the bar that is needed for the low shear region appears to be maintained by the secondary flow associated with the sharp bend. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology 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.)

In this paper, capabilities of state-of-the-art computational fluid dynamics (CFD) tools in the prediction of the flow-field around a multihull catamaran advancing in straight ahead motion at nonzero drift angles are investigated. CFD estimations have been provided by three research institutes by using their in-house codes: CNR-INM using Xnavis, IIHR using CFDShip-Iowa, and CNRS/ECN using ISIS. These allowed an in-depth comparison between different methodologies, such as structured overlapping grids versus unstructured grid, different turbulence models and detached eddy simulations (DES) approaches, and level-set (LS) versus volume of fluid (VoF). The activities were pursued within the NATO AVT-183 group "reliable prediction of separated flow onset and progression for air and sea vehicles," aimed at the assessment of CFD predictions of large three-dimensional separated flows. Comparison between estimations is provided for both integral and local quantities, and for wave-induced vortices. Validation is reported by comparison against the available experimental fluid dynamics (EFD) data. Generally, all the simulations are able to capture the main features of the flow field; grid resolution effects are dominant in the onset phase of coherent structures and turbulence model affects the dynamic of the vortices. Hydrodynamic loads are in agreement between the submissions with standard deviation of about 3.5% for the resistance prediction and about 7% for lateral force and yaw moment estimation. Wave-induced vortices are correctly captured by both LS and VoF approaches, even if some differences have been highlighted, LS showing well-defined and long life vortices. [ABSTRACT FROM AUTHOR]

In this paper, a deterministic stress decomposition is applied over the numerical three-dimensional flow solution available for a single volute centrifugal pump. The numerical model has proven in previous publications its robustness to obtain the impeller to volute-tongue flow interaction, and it is now used as starting point for the current research. The main objective has been oriented toward a detailed analysis of the lack of uniformity in the flow that the volute tongue promotes on the blade-to-blade axisymmetric pattern. Through this analysis, the fluctuation field may be retrieved and main interaction sources have been pinpointed. The results obtained with the deterministic analysis become of paramount interest to understand the different flow features found in a typical centrifugal pump as a function of the flow rate. Moreover, this postprocessing tool provides an economic and easy procedure for designers to compare the different deterministic terms, also giving relevant information on the unresolved turbulence intensity scales. Complementarily, a way to model the turbulent effects in a systematic way is also presented, comparing their impact on the performance with respect to deterministic sources in a useful framework, that may be applied for similar kinds of pumps. [ABSTRACT FROM AUTHOR]

In this study, flow behind rectangular vane type vortex generators mounted on a flat plate, is numerically simulated using the immersed boundary (IB) method. In the present work, the direct forcing IB method is employed because of its simplicity and high efficiency. Vortex generators of two different heights are numerically investigated. The height of vanes in the first case is close to the definition of submerged/lowprofile vortex generators while the other case is closer to the definition of a conventional vortex generator. The resultant highly three-dimensional flow and its transition to turbulence have been studied. Counterrotating vortices generated by these passive rectangular vortex generators are characterized. Streamwise evolution of non-dimensionalised maximum values of vorticity, vortex strength, streamwise velocity and wall-normal velocity are studied. The simulations show that the IB method in conjunction with DNS effectively simulates the time-dependent flow behind an array of passive vortex generators placed in an initially laminar boundary layer. [ABSTRACT FROM AUTHOR]

In the present paper, two-phase three-dimensional turbulent flow simulations are carried out by applying computational fluid dynamics (CFD) technique to the internal flow of a horizontal separator that is used in petroleum industry. Two different geometries are considered; the separator with a straight plate at the top and the separator with the straight plate on the side of the separator. Effects of the location, distance between the inlet of the separator and the diverter plate and inlet velocity on the separation efficiency are investigated by employing the standard k- ε turbulence model. For these purposes, three different distances between the straight diverter plate and the inlet to the separator (0.1 m, 0.15 m and 0.2 m) and four different velocities (0.25 m/s, 0.5 m/s, 0.75 m/s, and 1 m/s) are taken into account by means of Euler mixture model. It is revealed that the maximum separation efficiency is 99.772% when the mixture enters the separator from the top with the inlet velocity of 0.25 m/s and the plate is located 0.2 m away from the inlet section of the separator. An inverse correlation is detected between the inlet velocity and the efficiency of the separation since increasing the inlet velocity decreases the efficiency of the separation. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Dalian University of Technology / Dalian Ligong Daxue Xuebao is the property of Journal of Dalian University of Technology 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.)

This paper deals with the dynamic stability of a flexible liquid-filled rotor. On the basis of three-dimensional flow, the fluid perturbation motion is analyzed and the fluid-structure interaction equation is established, combining with continuity equation, the expression of fluid force exerted on rotor is derived in terms of Fourier series expansion. Considering the complex nonlinear relationship between fluid dynamic pressure and the rotor deformation function, they are expanded in terms of the eigenfunction of a dry rotor. The whirling frequency equation of a flexible rotor partially filled with liquid is obtained based on the rotor static equilibrium equation. Finally, the numerical technique is used to analyze the dynamic stability of the rotor system, and the influences of system parameters on unstable region are discussed. [ABSTRACT FROM AUTHOR]

Abstract The reliable prediction of the effect of various labyrinth parameters on leakage rate has not been reported enough and a theoretical prediction of the labyrinth performance for different geometries at different eccentricity ratios is required. The laminar, incompressible and three-dimensional flow in labyrinth seals is treated and the performance is obtained for different geometrical configurations of the seal and rotation of the shaft. The results show that both of the aspect ratio and the eccentricity ratio (rotor misalignment) have a significant effect on the performance of the seal. For a straight-through labyrinth seal the rotation of the shaft has a small and negligible effect on the leakage, while it makes considerable improvement of the performance of the up-the step seal. Also, it is found that the rotation of the shaft has an adverse effect on the performance of the down-the step seal. [ABSTRACT FROM AUTHOR]

Abstract A series of laboratory flume experiments were done in a large-scale 180° bend with non- cohesive sediment to find optimal or effective protection works at a bend. Detailed study of the scour and flow field dynamics with and without protection works was done. Spatially dense, high frequency velocity data were collected and analyzed to describe the pattern and magnitude of three-dimensional (3D) velocity throughout the bend. Characterizing the role of flow field dynamics on the pattern of deposition and erosion through experimental measurements provided valuable data about how such flow features contribute to scour and about the performance of the protection works. From the experimental results, it is revealed that for a perennial river it is not possible to protect from scour either with riprap or with submerged vanes alone. Protection from scour at a bend can be achieved with proper combination of these two works. First, submerged vanes can protect the toe, and, second, riprap can protect the upper part of the slope if it is not damaged through toe erosion. The experiments convincingly demonstrate the efficiency of this bank protection technique. [ABSTRACT FROM AUTHOR]

The present research explores the three-dimensional stretched flow of viscous fluid in the presence of prescribed heat (PHF) and concentration (PCF) fluxes. Mathematical formulation is developed in the presence of chemical reaction, viscous dissipation and Joule heating effects. Fluid is electrically conducting in the presence of an applied magnetic field. Appropriate transformations yield the nonlinear ordinary differential systems. The resulting nonlinear system has been solved. Graphs are plotted to examine the impacts of physical parameters on the temperature and concentration distributions. Skin friction coefficients and local Nusselt and Sherwood numbers are computed and analyzed. [ABSTRACT FROM AUTHOR]

In the present paper a theoretical investigation is performed to analyze heat and mass transport enhancement of water-based nanofluid for three dimensional (3D) MHD stagnation-point flow caused by an exponentially stretched surface. Water is considered as a base fluid. There are three (3) types of nanoparticles considered in this study namely, CuO (Copper oxide), Fe 3 O 4 (Magnetite), and Al 2 O 3 (Alumina) are considered along with water. In this problem we invoked the boundary layer phenomena and suitable similarity transformation, as a result our three dimensional non-linear equations of describing current problem are transmuted into nonlinear and non-homogeneous differential equations involving ordinary derivatives. We solved the final equations by applying homotopy analysis technique. Influential outcomes of aggressing parameters involved in this study, effecting profiles of temperature field and velocity are explained in detail. Graphical results of involved parameters appearing in considered nanofluid are presented separately. It is worth mentioning that Skin-friction along x and y- direction is maximum for Copper oxide-water nanofluid and minimum for Alumina-water nanofluid. Result for local Nusselt number is maximum for Copper oxide-water nanofluid and is minimum for magnetite-water nanofluid. [ABSTRACT FROM AUTHOR]