Search

This study investigates the effect of various structural parameters in plate-fin heat exchanger on the performance of a cascade refrigeration system (CRS). Focusing on five key factors—fin thickness, fin type, fin height, porosity, and element axial length—we analyze their contributions to COP, exergy destruction, and entropy production within the CRS. The results reveal that the fin type barely influences the CRS’ performance, the element axial length has the greatest impact, followed by fin height, porosity, and fin thickness, respectively. The COP of the CRS drops by 26.25 % as the element axial length increases from 124 mm to 136 mm, 23.67 % (23.08 %) as the fin height of perforated (straight) fin increases from 6.1 mm to 6.7 mm, and 10.27 % (10.38 %) as the fin thickness of perforated (straight) fin increases from 0.1 mm to 1.3 mm, and the exergy destruction increases by 42.42 %, 37 % (37 %), and 13 % (10.38 %), respectively. The effect of porosity on the CRS’ performance is opposite to that of other parameters. When the element axial length is 124 mm, the fin height is 6.1 mm, and the fin thickness is 0.1 mm, the COP of the CRS reaches the maximum value (0.689). The conclusion can provide data support for the performance optimization of CRS from the structure of the cascade heat exchanger.

This paper investigates the ventilation and heat dissipation performance of a 110 kV indoor substation under natural ventilation conditions using computational fluid dynamics (CFD). The objectives are to evaluate the influences of air inlet design parameters including location and size, and transformer load, on the airflow distribution, temperature field, and cooling efficiency. The study finds that staggered opposite inlets optimize cooling uniformity without airflow attenuation. Compared to a single inlet, the maximum transformer temperature is reduced by 1.3 °C and energy utilization increases by 9.1 % with staggered inlets. Increasing the inlet length ratio initially improves cooling until an optimal point (The length ratio is 1.10), while reducing the inlet height ratio decreases airflow and efficiency. With load increasing, the intake airflow rises but at a reduced rate, and the temperature difference can exceed 15 °C under high loads. In summary, optimizing inlet design enhances natural ventilation performance in indoor substations, but limitations exist at high loads, indicating supplemental mechanical ventilation may be required.

Abstract Background Severe combined immunodeficiency (SCID) is a group of fatal primary immunodeficiencies characterized by the severe impairment of T-cell differentiation. IL7R deficiency is a rare form of SCID that usually presents in the first months of life with severe and opportunistic infections, failure to thrive, and a high risk of mortality unless treated. Although recent improvements in early diagnosis have been achieved through newborn screening, few IL7R-related SCID patients had been reported in the Chinese population. Case presentation Here, we retrospectively analyzed a case of SCID in a 5-month-old girl with symptoms, including severe T-cell depletion, recurrent fever, oral ulcers, pneumonia, hepatosplenomegaly, bone marrow hemophagocytosis, and bacterial and viral infections. Whole-exome sequencing (WES), quantitative PCR (qPCR), and chromosome microarray analysis (CMA) were performed to identify the patient’s genetic etiology. We identified a 268 kb deletion and a splicing variant, c.221 + 1G > A, in the proband. These two variants of IL7R were inherited from the father and mother. Conclusions To our knowledge, this is the first report of whole IL7R gene deletion in combination with a pathogenic splicing variant in a patient with SCID. This deletion also expands the pathogenic variation spectrum of SCID caused by IL7R. The incorporation of exome-based copy number variant analysis makes WES a powerful molecular diagnostic technique for the clinical diagnosis of pediatric patients.

Abstract This study presents a thermodynamic–dynamic model of a free‐piston Stirling engine (FPSE) with nonlinear coefficients of spring, load damping, and pressure for working spaces. The effects of the nonlinear coefficients of hardening and softening springs on the movement and operating frequency of a displacer and piston are investigated. Subsequently, the influences of the nonlinear pressure terms of the working space and buffer spaces, as well as the nonlinear coefficients of the load on the amplitudes of the two pistons, frequency, and output powers are discussed. The results indicate that the low nonlinear coefficients of the spring have a minor effect on the amplitudes and frequency. As the high nonlinear coefficients of the hardening spring increase, the amplitudes and output power decrease, while the frequency increases. As the nonlinear terms of the softening spring increase, the amplitudes and output power reach maximum values, but the frequency is reduced by 3.55%. The effects of the nonlinear pressure terms on the amplitudes and output power are not evident. However, an increase in the nonlinear load leads to a significant decrease in the FPSE's performance.

Currently, most integral simulations of condensers are based on the assumption of uniform intake air, which differs from real scenarios and leads to imprecise circuit designs. To obtain the actual air velocity distribution and reflect its impacts in the model, a comprehensive methodological system is established in this study. The implementation involves employing the porous media model to simulate air velocity distribution and utilizing the results as the air inlet condition of the distributed parameter model to achieve an integral simulation of condensers. The results indicate that the air velocity distribution is significantly non-uniform. The distribution of air velocity has a limited impact on the performance of single-row tube condenser, but has a significant effect on double-row tube condenser. Minimizing the discrepancy in the positioning of each sub-flow circuit and arranging tubes with large temperature differences in the high air velocity area can enhance heat transfer performance, the “z''-shaped double-tube parallel circuit designed by these theories can continue to improve the heat transfer performance by 2.8 % compared to the single-tube serial circuit with countercurrent arrangement within the accuracy limits of the simulations, and marking a 43.5 % improvement compared to the conventional zigzag-shaped single-tube serial circuit.

Abstract Background Rhizomelic limb shortening with dysmorphic features (RLSDF) has already been a disorder of the rare autosomal recessive skeletal dysplasia, just having a few reported cases. RLSDF is caused by protein kinase domain containing, cytoplasmic(PKDCC)gene variants. In this study, we describe the clinical features and potential RLSDF molecular etiology in a fetus from China. Methods Genomic DNA (gDNA) extracted from the fetal muscle tissue and parents’ peripheral blood was subjected to chromosomal microarray analysis (CMA) and trio-based whole exome sequencing (Trio-WES). The candidate pathogenic variants were verified by using Sanger sequencing. Results Trio-WES identified two compound heterozygous variants in PKDCC, c.346delC (p.Pro117Argfs*113) and c.994G > T (p.Glu332Ter), inherited from the father and mother, respectively. Both variants are classified as pathogenic according to American College of Medical Genetics and Genomics guidelines. Conclusions We reported the first prenatal case of RLSDF caused by PKDCC in the Chinese population. Our findings extended the variation spectrum of PKDCC and emphasized the necessity of WES for the early diagnosis of skeletal dysplasia and other ultrasound structural abnormalities in fetuses.

The performance analysis and optimization of a γ-type free-piston Stirling engine (FPSE) are conducted using Response Surface Methodology (RSM) and Grey Relation Analysis (GRA). The input-output parameters table is determined by the RSM. A regression model is presented to investigate the influence of structural parameters of FPSE on its performance. The relation coefficients for the four output parameters obtained from the RSM are determined to be 0.9980, 0.9983, 0.9999, and 0.9995, respectively, thus unequivocally demonstrating the exceptional precision of the RSM model. Also, the relationship between displacer and piston amplitudes, operating frequency, and output power and these parameters of Stirling engine is presented via 3D surface plots. The performance of the FPSE is optimized using the desirability approach and GRA, respectively, followed by a comparison of four groups of optimization results to determine the most suitable model. The maximum output power achieved is 78.02 W, with corresponding operating frequency, displacer amplitude, and piston amplitude values of 60.24 Hz, 2.55 mm, and 7.27 mm. Finally, by comparing pre- and post-optimization, the output power is increased by 36.85%. The GRA exhibits superior optimization compared to the RSM, thus providing valuable guidance for enhancing the optimization of FPSE in this study.

The advantage of coupling different heat sources with each thermoacoustic core unit in a three-stage looped traveling-wave thermoacoustic system is used to solve the application problem of multiple waste heat sources. The effects of the heat-side heat exchanger temperature, the resonance tube radius and length, and their interaction terms on the thermoacoustic thermodynamic properties are analyzed using response surface methodology on the premise that thermoacoustic core structures remain unchanged. The results indicate that prediction deviations for acoustic power, thermoacoustic conversion efficiency, and relative Carnot efficiency are within ±9%, ±3%, and ±3%, respectively. The acoustic power can be improved by increasing the hot-side heat exchanger temperature and the resonance tube radius. Under the same heat source conditions, the acoustic power, thermoacoustic conversion efficiency, and relative Carnot efficiency of the optimized thermoacoustic system show the highest increases of 49.63%, 4.82%, and 3.20%, respectively, compared to the non-optimized thermoacoustic system. The optimized variable-temperature system not only has higher thermodynamic efficiency compared with the optimized constant-temperature system but also can realize the complementary regulation among the thermoacoustic engine units by matching decreasing-gradient variable temperature and increasing-gradient variable radii and effectively broaden the working temperature range of the looped thermoacoustic system.

Microchannel flat-tube heat exchangers (MCHX) have been introduced into refrigeration systems due to their high efficient heat transfer, lightweight and compact structure. In this work, a MCHX was introduced into a household freezer as the evaporator. The dynamic characteristics and performance were experimentally investigated and compared to the freezer with a traditional circular tube evaporator. Results showed that the refrigerant charge, compressor-on ratio, and daily power consumption of the freezer with the MCHX were reduced by 5.4%, 4.4% and 4.8%, respectively. In contrast to circular tubes, microchannel tubes in evaporators have a flattened rectangular with multiple flow channels. This design increases the surface area for heat transfer, allowing for enhanced heat transfer performance. The decreased refrigerant charge and good heat exchange performance for the MCHX evaporator contribute to a lower outlet temperature, improved cooling efficiency and lower power of the compressor. Results verified that the MCHX could be used as the evaporator in household freezers to reduce the power consumption and improve the system performance.

The distributed parameter method is adopted to establish a simulation model of the indoor unit of a split-type household air conditioner with a diameter of 5 mm. The circuits of forward and reverse cross are proposed, and the effects of different circuits on the thermal-hydraulic performance of heat exchanger are revealed. Compared with the prototype, the heat load of the forward and reverse cross is increased more obviously. The forward and reverse cross can realize the strengthening of the heat load by changing the spatial distribution of heat load and temperature difference. The forward and reverse cross under the cooling condition can improve the temperature difference of the second row. The heat loads of the two-phase zone and the vapor phase zone increase to a certain extent. Under the cooling condition for circuit-3, the heat load is increased by 6.65%, and the pressure drop in refrigerant side is slightly increased. Under the heating condition for circuit-3, the heat load and pressure drop in refrigerant side are similar to that of the prototype. Meanwhile, the circuit-3 has the most obvious improvement effect on the non-uniformity of pressure drop under different conditions.

In this paper, an off-set fin heat exchanger (OSFHE) and a flying-wing fin heat exchanger (FWFHE) were developed for the condenser of a condensing clothes dryer. They were used to replace the slit fin heat exchanger (SFHE), which is the prototype condenser. Performance parameters, like condensation rate, IEC energy efficiency index (EEI) and specific moisture extraction rate (SMER), were used to assess the dehumidification performance of the heat exchangers and the drying performance of the dryer. Though the fin areas of OSFHE and FWFHE are 20% and 34.2% less than that of SFHE, the experiment results indicated that OSFHE and FWFHE had a faster condensation rate than SFHE during the main drying stage. And the heat exchanger with a faster condensation rate also led to less power consumption of the dryer in most tests. Compared with using SFHE, using OSFHE could decrease the EEI of the dryer by 0.43%. Using FWFHE could reduce the EEI of the dryer by 1.19% and improve the EU energy efficiency class of the dryer from Class C to Class B. Both OSFHE and FWFHE are able to replace SFHE and become a new generation of condensers for clothes dryers.

In this study, a numerical model of two-phase flow boiling in a rod bundle channel was developed to investigate the influence of spacer grid's arrangement on thermal-hydraulic characteristics and critical heat flux (CHF). It was verified well by comparing with the experimental data obtained from 2006 look-up table, and the relative errors were within ±20% in most conditions. On this basis, taking a complex 5 × 5 rod bundle channel as an example, four different geometric models including bare rod bundle, rod bundles with upstream, downstream and two-Span spacer grid were established, respectively. It was found that upstream spacer grid has little influence on CHF, while CHF could be significantly improved by downstream spacer grid. Convective heat transfer coefficient of liquid phase can be increased a lot at the region of spacer grid, but enhancement effect of heat transfer only keeps a limited distance as the decreases of mixing effect of mixing vane. According to the distribution of secondary flow, the intensity of secondary flow caused by upstream spacer grid is weakened at the region of downstream spacer grid. Moreover, spacer grid would result in an increase of pressure drop, causing a certain pressure on the pump load.

The heat dissipation performance of an intelligent power module (IPM) is an important part of power electronics. This study conducts a parametric impact analysis and optimization on the thermal-hydraulic performance of an IPM heat sink. A fluid–solid coupling CFD numerical calculation model for the IPM heat sink was established. The influences of the number of pipes, pipe diameter, pipe connection method on IPM maximal temperature, pressure drop, Nusselt number, thermal resistance and entropy generation were studied. Results show that the large pipe number, small pipe diameter can reduce the IPM maximal temperature and thermal resistance, but increase pressure drop and entropy generation. Considering the maximum temperature and pressure drop as multiple targets, the structural parameters of the IPM heat sink were optimized using response surface methodology. Analysis of variance was used to analyze the influence weight of the parameters on the performance of the heat sink, and regression models were obtained. Finally, multi-objective optimization was used to achieve the lowest IPM maximum temperature with the minimal increase in pressure drop. The results showed that the maximum temperature without an increase in pressure drop decreased by 4.55 K when compared with that of the original structure.

A multiphase flow numerical model based on Eulerian is built to simulate the characteristics of subcooled boiling. The thermodynamic performance in a single rod channel with/without spacer grid are obtained by numerical simulation, and the influence of spacer grid on flow and heat transfer characteristics of subcooled boiling is studied. The model is verified by comparing with the experimental results. After passing through the spacer grid, the high-temperature zone departures from the surface of fuel rod moves towards the cold wall. This impact extends to a certain downstream distance, and then it gradually declines. The influence of different components in spacer grid on the pressure drop is detailed. The pressure drop with spacer grid is 5% higher than that without spacer grid, within the allowable design limitation. The maximum value of section average secondary flow can reach 13.5% of the inlet velocity, indicating that the mixing vanes have stronger ability to produce transverse flow. The influence length of spacer grid on heat flux partitioning is about 27Dh. The effect of spacer grid on the wall heat flux partitioning mainly lies in the decrease of the evaporation heat flux, benefited to reduce the risk of nuclear reactor approaching DNB.

In this paper, an innovative method of adopting a piping insert with an abrupt contraction or expansion structure has been proposed to eliminate undesirable thermally driven gas oscillations in cryogenic systems. In addition, the influences of the piping inserts’ geometrical parameters and position on the performance of thermoacoustic oscillation in cryogenic systems have been investigated. A series of simulations has been conducted, and simulation bifurcation diagrams show that thermoacoustic oscillation can be completely stopped, which, in other words, is called the amplitude death (AD) phenomenon. When the pipeline inserts are equipped in the cold part, AD can be achieved regardless of the pipeline inserts’ radius. When the pipeline inserts are located in the warm part, AD can be realized by the pipe inserts with an abrupt contraction. The identification of nonlinear characteristics of different state transitions with different insert geometries is further conducted by unfolding these original time series in an embedding space. The nonlinear change process of thermoacoustic oscillation is demonstrated in the phase space diagrams. As the insert radius increases, the system transforms from a periodic state to a quasi-periodic state and then from a quasi-periodic state to an AD state. This work will have practical impacts on the design of oscillation-free piping systems.

Stability of objects in fluid flow is an interesting and significant subject in many fields. From thermodynamics point of view, the constructal law by Bejan et al. proposed that in some scenario, objects tend to be stable when the drag reaches maximum. To investigate the relation between drag and stable positions, we analyzed two simple cases by the finite element method: an elliptical cylinder and a rectangular cylinder immersed in 2D uniform laminar flow. The ellipse is stable when its major axis is perpendicular to the mainstream and the drag reaches maximum; yet the rectangle is stable when the length is perpendicular to the mainstream, with drag ranging from minimum to maximum depending on its aspect ratio. Our results show that there is no universal relation between drag and stability. Keywords: Stability, Constructal law, Laminar flow, Computational fluid dynamics

According to the relevant theories on duality relation, the summation of the extractable information of a quanton’s wave and particle properties, which are characterized by interference visibility V and path distinguishability D, respectively, is limited. However, this relation is violated upon quantum superposition between the wave-state and particle-state of the quanton, which is caused by the quantum beamsplitter (QBS). Along another line, recent studies have considered quantum coherence C in the l1-norm measure as a candidate for the wave property. In this study, we propose an interferometer with a quantum which-path detector (QWPD) and examine the generalized duality relation based on C. We find that this relationship still holds under such a circumstance, but the interference between these two properties causes the full-particle property to be observed when the QWPD system is partially present. Using a pair of polarization-entangled photons, we experimentally verify our analysis in the two-path case. This study extends the duality relation between coherence and path information to the quantum case and reveals the effect of quantum superposition on the duality relation.

The present study proposes a model to predict the heat transfer coefficient in R134a liquid–vapor two-phase pulsating flow boiling in an evaporator using the experimental data and response surface methodology (RSM). The model is based on the current existing empirical correlation for R134a liquid–vapor two-phase continuous flow with an imposed modification factor. The model for the imposed modification factor is the function of the pulsating period and inlet/outlet vapor quality, which is obtained using the limited experimental data. An analysis of variance (ANOVA) is carried out to test the significance of the model and normal probability of residuals is analyzed as well. Results show that the regression model produces a mean error of −4.3% and a standard deviation of 15.4%, compared to experimental results. Of the data 95.1% is contained inside a ±50% error window, which indicates that the proposed model could predict the heat transfer coefficient of R134a liquid–vapor two-phase pulsating flow boiling well.

Boson sampling is a promising candidate for quantum supremacy. It requires to sample from a complicated distribution, and is trusted to be intractable on classical computers. Among the various classical sampling methods, the Markov chain Monte Carlo method is an important approach to the simulation and validation of boson sampling. This method however suffers from the severe sample loss issue caused by the autocorrelation of the sample sequence. Addressing this, we propose the sample caching Markov chain Monte Carlo method that eliminates the correlations among the samples, and prevents the sample loss at the meantime, allowing more efficient simulation of boson sampling. Moreover, our method can be used as a general sampling framework that can benefit a wide range of sampling tasks, and is particularly suitable for applications where a large number of samples are taken.

The purpose of this study was to identify functional genetic variants in the promoter of tumor necrosis factor superfamily member 15 (TNFSF15) and evaluate their effects on the risk of developing gastric adenocarcinoma. Forty DNA samples from healthy volunteers were sequenced to identify single nucleotide polymorphisms (SNPs) in the TNFSF15 promoter. Two TNFSF15 SNPs (-358 T > C and -638 A > G) were identified by direct sequencing. Next, genotypes and haplotypes of 470 gastric adenocarcinoma patients and 470 cancer-free controls were analyzed. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by logistic regression. Serologic tests for Helicobacter pylori infection were measured by enzyme-linked immuno-sorbent assay (ELISA). Subjects carrying the TNFSF15 -358 CC genotype were at an elevated risk for developing gastric adenocarcinoma, compared with those with the -358 TT genotype (OR 1.42, 95% CI, 1.10 to 2.03). H. pylori infection was a risk factor for developing gastric adenocarcinoma (OR 2.31, 95% CI, 1.76 to 3.04). In the H. pylori infected group, subjects with TNFSF15 -358 CC genotype were at higher risks for gastric adenocarcinoma compared with those carrying -358 TT genotype (OR: 2.01, 95%CI: 1.65 to 4.25), indicating that H. pylori infection further influenced gastric adenocarcinoma susceptibility. The -358 T>C polymorphism eliminates a nuclear factor Y (NF-Y) binding site and the -358 C containing haplotypes showed significantly decreased luciferase expression compared with -358 T containing haplotypes. Collectively these findings indicate that functional genetic variants in TNFSF15 may play a role in increasing susceptibility to gastric adenocarcinoma.

PurposeXeroderma pigmentsum group F (XPF) plays a pivotal role in DNA nucleotide excision repair and has been linked to the development of various cancers. This study aims to assess the association of XPF genetic variants with the susceptibility to esophageal squamous cell carcinoma (ESCC) in Chinese population.MethodsThis two-stage case-control study was conducted in a total of 1524 patients with ESCC and 1524 controls. Genotype of XPF -673C>T and 11985A>G variants were determined by polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP). Logistic regression analysis was performed to estimate odd ratios (ORs) and 95% confidence intervals (95% CI).ResultsOur case-control study showed that XPF -673TT genotype was associated with a decreased risk of ESCC compared with CC genotype in both case-control sets (Tangshan set: OR = 0.58; 95%CI = 0.34-0.99, P = 0.040; Beijing set: OR = 0.66; 95%CI = 0.46-0.95, P = 0.027). Stratified analyses revealed that a multiplicative interaction between -673C>T variant and age, sex or smoking status was evident (Gene-age: Pinteraction = 0.002; Gene-sex: Pinteraction = 0.002; Gene-smoking: Pinteraction = 0.002). For XPF 11985A>G polymorphism, there was no significant difference of genotype distribution between ESCC cases and controls.ConclusionThese findings indicated that genetic variants in XPF might contribute to the susceptibility to ESCC.

Efficient ventilation and heat dissipation in indoor substations are crucial for the stable operation of transformers. This study investigates the impact of inlet and outlet positions on ventilation and heat dissipation performance in a 110 kV indoor substation using CFD. A model of the 110 kV main transformer chamber is developed. Twelve combinations of inlet and outlet positions are analysed. Inlet positions include side walls parallel to radiators, side walls perpendicular to radiators and both side walls perpendicular to radiators. Outlet positions include the top of the chamber, the side of the inlet, adjacent to the inlet, and opposite inlet. Results demonstrate that locating outlets at the top of the chamber reduces transformer temperature by 0.5-1.6 °C and increases energy utilization by 8.6%-24.8% regardless of inlet position. Two opposite inlets perpendicular to radiators allows even air distribution between radiators. This configuration reduces transformer temperature by 3.4 °C when the outlet is located at the top of the chamber. Overall, the optimal ventilation design involves top chamber outlets and inlets on opposite walls perpendicular to radiators. [ABSTRACT FROM AUTHOR]

A mathematical model based on energy and exergy methods is established to analyze the performance of an auto-cascade refrigeration system at varying compositions of the mixed refrigerants, condensation temperature, evaporation temperature, and vapor quality at the condenser outlet. Furthermore, grey correlation theory is employed to assess the correlation degrees between refrigerant mass fractions and system performance, enabling the identification of the state that has the greatest impact on the output parameters. It has been concluded that while maintaining a constant mass fraction of R600a, an increase in the mass fraction of R1150 (State 1) leads to a higher cooling capacity but a decrease in exergy efficiency. The performance decreases with the increase of the R600a mass fraction (State 2) as the R1150 mass fraction is unchanged. When the component of R14 is constant while the other two components R600a/R1150 vary (State 3), and the COP exists as the optimal value. The mixture of R600a/R1150/R14 with a mass fraction of 0.5:0.2:0.3 has better performance at COP of 0.5027 and exergy efficiency of 29.43% under a condensation temperature of 30 °C. Based on the results of the grey correlation degree, the greatest factor in cooling capacity is State 1, while the COP and exergy efficiency are primarily controlled by State 3. [ABSTRACT FROM AUTHOR]

In this paper, the effects of slotted height at different fin pitches are analyzed in detail, aiming to investigate the function and optimal ratio of slotted height to fin pitch. In the cases of high Reynolds number for louver fin, the "bimodal phenomenon" of heat transfer coefficient begins to appear with the increasing slotted height. As the slotted height is about half of the fin pitch, the heat transfer coefficient has a local minimum value, of which there are two peaks on both sides. However, the pressure drop has been increasing with the increasing slotted height. The optimal slotted height under different fin pitches is more instructive than the optimal louver angle. For slit fin, the heat transfer coefficient increases first and then decreases with the increasing slotted height, so does the pressure drop. Meanwhile, as the slotted height is about 0.3~0.45 times and 0.5~0.65 times of fin pitch for louver fin and slit fin, respectively, the comprehensive performance can reach a maximum. The optimal comprehensive performance under 1.2 mm fin pitch is greater than the optimal comprehensive performance under 1.8 mm fin pitch. For lower Reynolds numbers, the optimal comprehensive performance of louver fin is roughly similar to the slit fin. For higher Reynolds numbers, the optimal comprehensive performance of louver fin is greater than that of slit fin. [ABSTRACT FROM AUTHOR]

Acoustic streaming is the time-averaged flow induced by acoustic waves inside the fluid medium. Much attention has been paid to the streaming flow at the microscale, with the rapid development of micro-fluidics and significant demand for the microscale manipulation of fluid or particles. Recently, the streaming flow at the audible or lower frequency (10 Hz~10 kHz) has been found to be closely associated with local structures, like a sharp edge in the micro-channel. By its strong magnitude and low cost, this kind of streaming flow has been applied in various fields. However, the mechanisms behind this non-classical Rayleigh streaming are still not very clear, though its high sensitivity to the thickness of the acoustic boundary-layer and unstable streaming pattern under high forcing amplitude have been demonstrated. In this study, experimental work has been conducted, with the help of the particle imaginary velocimetry platform, to reveal the influence of frequency and vibrating amplitude on the streaming flow field around a sharp edge with 90°, and its characterized spatial dimension. The scaling law concerning the vibration amplitude and streaming velocity has been come up with, and the parameter frequency is also included. The expression f -1/6va 2 ~vsy,max demonstrates a good prediction in terms of the streaming magnitude, in comparison with experimental results. [ABSTRACT FROM AUTHOR]