Plate Spacing Research Articles

Convective heat transfer by nanofluid jet impingement cooling on automobile radiator with nozzle plate spacing

Nanofluids are a type of emerging heat transfer fluid with great promise for thermal engineering due to its high heat transfer coefficients. Improving heat transmission remains an ongoing task in engineering fields as diverse as semiconductor technology and high-performance vehicles. This paper investigates and compares the jet impact heat transfer coefficient, thermal conductivity, and viscosity of nanofluids with those of a base fluid in an automobile radiator with nozzle plate spacing. Aluminium oxide (Al2O3) and deionised water were selected as the working fluids, and they were used in varying quantities ranging from 0 to 1 volume percent. The nanofluids were prepared using a two-step method with the aid of an ultrasonic homogeniser. The results reveal that the heat transfer coefficient increased by 11.68% at a nanofluid concentration of 1% when nanoparticles were suspended in the base fluid. Furthermore, a 45-49% improvement in the heat transfer coefficient was recorded using a nanoparticle volume concentration of 1% compared to the base fluid.

Numerical study on heat transfer characteristics of multiple air jet impinging at lower jet to plate spacing

For multi-nozzle jet impinging, the effects of impinging distance (Z/D), streamwise spacing (X/D) and spanwise spacing (Y/D) on heat transfer characteristics should be considered. The heat transfer characteristics for multi-nozzle jet impinging structure with different nozzle spacings were investigated by numerical method. When the impinging distance is constant (Z/D = 0.2), the effects of Reynolds number (Re = 12,000–28,000), streamwise spacing (X/D = 3, 4, 6, 8, 10), spanwise spacing (Y/D = 3, 4, 6, 8, 10) and impinging nozzle arrangement (in-line structure and staggered structure) are considered. The Standard k-ε model was chosen for simulating after comparison to the relevant experimental values. The influences of nozzle spacing and the Reynolds number on the heat transfer characteristics were examined. The Colburn factor j and friction factor f were investigated in relation to Re. The performance criteria η of the Reynolds number ranging from 12,000–28,000 was calculated. The calculations indicated that the jet impinging heat transfer coefficient is highest under the structure of X/D = 3 and Y/D = 3. Compared to the in-line arrangement, the staggered arrangement has a higher average Nusselt number. This is because the turbulent kinetic energy of the staggered structure on the impinging target surface is larger and the heat exchange efficiency is higher. However, the gap between the average Nusselt numbers of the staggered and in-line nozzle arrangements decreases with an increase in Reynolds number. Given the same heat exchange surface, the average Nusselt number is highest under the X/D = 8 and Y/D = 8 arrangements. This is because the larger the impinging nozzle spacing, the fewer the number of nozzles. Therefore, the greater the speed of the gas reaching the nozzle outlet, the greater the average Nu of the target surface.

Damage effects of aluminum alloy honeycomb sandwich panel double-layer structure induced by reactive projectile hypervelocity impact

In this paper, the experiments of Al2024 and reactive projectiles with hypervelocity impact on aluminum alloy honeycomb sandwich panel double-layer structure respectively were carried out by using two-stage light-gas gun, and the impact processes were recorded through high speed camera. According to the analysis of the experimental results, the debris clouds motion process and the damage effects on double-layer structure were compared. The damage enhancement mechanism of reactive projectile was revealed through numerical simulation and theoretical methods. The impact-induced detonation reaction of the reactive projectile can significantly reduce the "channel effect" of the honeycomb sandwich panel by destroying the honeycomb core cell wall, increase the perforation on the back facesheet of the honeycomb sandwich panel, and generate the debris cloud with higher temperature and faster expansion velocity. The debris cloud induced by the reactive projectile has a larger load distribution area on the rear plate, avoiding the concentration of loads in the center of the rear plate, and cause large area impact and thermal combined damage effects on the rear plate and internal space of the double-layer structure, while ensuring that the target structure cannot be penetrated. The reactive projectile efficiently applies the kinetic energy and chemical energy released by the impact-induced reaction to the interior of the target structure, the waste of kinetic energy caused by whole structure penetration can be avoided, resulting in significantly higher damage effects than the inert Al2024 projectile.

Wernicke encephalopathy

Introduction: Wernicke’s encephalopathy is a life-threatening disease caused by thiamine deficiency with the development of damage to brain. Objective: to analyze the etiological factors, clinical, laboratory and instrumental data, as well as clinical outcomes of Wernicke’s encephalopathy.Material and мethods: the study included 36 patients with Wernicke’s encephalopathy. the average age of patients was 54.5 ± 15.9 years, women were 52.8%, men — 47.2%.Results: the most common causes of Wernicke’s encephalopathy were long-term alcohol abuse and diseases of the gastrointestinal tract or liver. A decrease in the level of wakefulness was detected in 63.9% of patients at the onset of the disease and in 72.2% during the entire period of hospitalization. In all patients, MRI of the brain revealed symmetrical areas of increased signal in the T2 FLAIR and DWI modes in the medial parts of both thalami, and in some cases also in the area of the quadrigeminal plate and/or periaqueductal space of the midbrain.Conclusion. Assessment of blood thiamine levels is not mandatory before starting therapy; thiamine administration should be started without laboratory confirmation of deficiency. Preventive administration of thiamine at a dose of 1000 mg per day is justified for any clinical suspicion of Wernicke’s encephalopathy.

The Elimination of Levofloxacin from High-Salinity Wastewater via the Electrochlorination Process

The electrochlorination (E-Cl) process has attracted much attention as it is a highly efficient method for treating organic compounds in hypersaline wastewater. In this study, the E-Cl process was utilized for the removal of antibiotics. The optimal experimental conditions were determined to be a NaCl concentration of 100 mM, a current density of 1.5 mA/cm2, a pH of 7.0, and a plate spacing of 1 cm, with a levofloxacin (LEV) degradation efficiency reaching as high as 99% using this setup. The effects of the presence of other ions and humic acid on the E-Cl process were investigated, and it was found that the degradation of LEV was not significantly affected by the presence of coexisting substances. In addition, free chlorine was identified as the primary active species for the degradation of LEV by means of a quenching experiment. It was demonstrated by 3D EEM and TOC that LEV was not completely mineralized and that intermediate products may be present. In order to reveal the degradation pathways of LEV, its degradation products were also analyzed via LC-MS, and some possible pathways of LEV degradation in this system were proposed. The successful degradation of LEV demonstrated that the E-Cl process is an efficient and promising technique for the treatment of organic pollutants in high-salinity wastewater.

Treatment of electroplating wastewater using electrocoagulation and integrated membrane.

Electroplating wastewater contains heavy metal ions and organic matter. These contaminants not only endanger the environment but also pose risks to human health. Despite the development of various treatment processes such as chemical precipitation MBR, electrocoagulation (EC) ceramic membrane (CM), coagulation ultrafiltration (UF) reverse osmosis (RO), and CM RO. These methods are only effective for low concentrations of heavy metals and struggle with high concentrations. To address the challenge of treating electroplating wastewater with high heavy metal content, this study focuses on the wastewater from Dongfang Aviation Machinery Processing Plant. It introduces an EC and integrated membrane (IM) treatment process for electroplating wastewater. The IM comprises microfiltration (MF) membrane, nanofiltration (NF) membrane, and RO membrane. Results indicated that under specific conditions, such as a pH of 8, current density of 5 A/dm2, electrode plate spacing of 2 cm, 35 min of electrolysis time, and influent pH of 10 for the IM, removal rates of Zn2+, Cu2+, Ni2+, and TCr in the wastewater exceeded 99%. The removal rates of chemical oxygen demand (COD), suspended solids (SS), total phosphorus (TP), total nitrogen (TN), and petroleum in wastewater exceed 97%. Following a continuous cleaning process, the membrane flux can consistently recover to over 94.3%.

High Speed Impact Testing of UHMWPE Composite Using Orthogonal Arrays

BackgroundUltra high molecular weight polyethylene composites are fiber based composites used in armor applications. While some characterization has been conducted experimentally, this study varies multiple parameters simultaneously to investigate material response under a wide range of conditions.ObjectiveThis work focuses on characterizing the response of Dyneema® HB26 hard laminate composites under high-speed impacts to examine the influence of plate diameter, clamping pressure, and plate spacing on target performance. Additionally, micro Computer Tomography scans are used to nondestructively evaluate the damage evolution in the targets.MethodsThese scan results are used in concert with more traditional armor performance metrics to evaluate the effect of various parameters using the method of orthogonal array analysis. This technique allows for multiple variables to be investigated in the same test series, saving time and budget while still providing quality results across a range of variables and variable values.ResultsWe conclude that of the parameters investigated, the plate spacing parameter has the largest effect on performance, followed by the plate diameter. Bolt torque was found to not have a significant impact on results, indicating that an edge clamping pressure is not critical to material response. Additionally, by examining the high resolution scans, we can quantify the damage with an effective damage angle and that this angle is a good predictor of performance. ConclusionFinally a damage theory involving the effective bending strength of the plates is discussed as an explanation for all of the results observed in this test series.

Numerical Study on the Effects of Helix Diameter and Spacing on the Helical Pile Axial Bearing Capacity in Cohesionless Soils

The methods employed to calculate the axial bearing capacity of a helical pile depends on the shear failure model around the pile, which is also influenced by the spacing and diameter of the helical plates. However, studies on the transition of the failure mode and the load transfer mechanism with the change of helical plate spacing and diameter in cohesionless soil subjected to axial compressive load have been limited. Thus, this paper investigated the effects of helix diameter and spacing on the axial compressive load-bearing capacity, shear failure model, and load transfer mechanism of helical piles with two helical plates embedded in the homogeneous medium and dense sands, as well as in the stratified medium to very dense sand. Axial loading tests on helical piles with various helix diameters and spacings were simulated using a two-dimensional finite element program with axisymmetric modeling to obtain the load-settlement curve, which was later used to estimate the ultimate bearing capacity of the helical piles. The ultimate bearing capacity of the helical piles was also computed using the conventional methods, i.e., the individual bearing and cylindrical shear methods, and then compared to the numerical-based axial bearing capacity. The stress-strain behaviors of pile and soil were modeled using the Linear Elastic and Mohr-Coulomb material models, respectively. The results show that the numerical-based ultimate bearing capacity of a helical pile increased with increasing the diameter and spacing of the helix. However, the ultimate bearing capacity computed using conventional methods did not show this trend. Then, the transition from the cylindrical shear to the individual bearing failure mechanism occurred at a spacing ratio (i.e., helical plate spacing divided by its diameter) of about two. Ultimately, the load transfer curves indicate that the helical plates mainly supported the applied load.

Local Heat Transfer of a Smooth Flat Plate Impinged by Multiple Jets

A smooth flat plate impinged by multiple jets is investigated for the local heat transfer using a thermal imaging technique. An inline arrangement of circular jets with all side exit scheme is implemented. Jets are introduced from a 4 mm thick orifice plate. The jet diameter is 3 mm. Reynolds numbers (based on the jet diameter) range covered in this study are from 500 to 15,000. The variation of the local, spanwise average, and overall average Nusselt numbers is investigated for nozzle exit to targeted plate spacing of 0.5 d–6 d, where d is the jet diameter. A periodic pattern is witnessed in the local Nusselt number with a drop in its amplitude in the spanwise direction. For a given Reynolds number, the local and average Nusselt numbers are influenced by nozzle exit to targeted plate spacing. The influence of Reynolds number on the local and average Nusselt number is captured using Re n . The value of n is found to be 0.5 and 0.6 depending on the Reynolds number range. In comparison with a single jet, multiple jet impingement on a smooth flat plate deteriorates the local Nusselt number. A semi-empirical correlation that captures the periodic nature of local and average Nusselt numbers is suggested.

Time-resolved measurement of acoustic density fluctuations using a phase-shifting Mach-Zehnder interferometer.

Phase-shifting interferometry is one of the optical measurement techniques that improves accuracy and resolution by incorporating a controlled phase shift into conventional optical interferometry. In this study, a four-step phase-shifting interferometer is developed to measure the spatiotemporal distribution of acoustic density oscillations of the gas next to a rigid plate. The experimental apparatus consists of a polarizing Mach-Zehnder interferometer with a polarization camera capable of capturing four polarization directions in one shot image and it is used to measure the magnitude and the phase of density fluctuations through a duct of rectangular cross section connected to a loudspeaker. The results are compared with the well-established thermoacoustic theory describing the thermal coupling between acoustic oscillations and rigid boundaries, and the results show a very good agreement for various ratios of the (frequency-dependent) thermal boundary layer thickness to the plate spacing. This measurement technique could be advantageously employed to analyze more complex heat transfer processes involving the coupling of acoustic oscillations with rigid boundaries.

Collection of nanoparticles by electrostatic precipitation operating over a wide range of electric fields

ABSTRACT In the electrostatic precipitation of microparticles, it is common to evaluate the voltages between the corona onset voltage and the breakdown point. However, the charging of particles in the nanoscale size range mainly occurs by diffusion, suggesting the possibility of its occurrence, even at low values. This paper investigates the implications of a wide range of electric fields applied in the collection of nanoparticles (6.15–241.4 nm). Two electrostatic precipitators (P.I. and P.II.), both with plates 10 cm high and 30 cm long, but with different plate spacings (4 and 6.5 cm), were tested using three air velocities (1.9, 2.9, and 3.9 cm/s) and 36 electric fields (0.0 − 5.0 kV/cm). Under the highest electric fields, both precipitators showed efficiencies above 99.9%. Furthermore, nanoparticles were collected before the corona onset voltage, with efficiencies of around 28% (P.I.) and 35% (P.II.). Even though no current was detected by the high voltage source, charges on the particles were measured in electric fields lower than 3.0 kV/cm. The higher the applied voltage, the higher the residual charge of the particles at the precipitator outlet. It is expected that the findings of this work should contribute to the technological development of electrostatic processes for air treatment.

Local Heat Transfer Distribution On Thin Metal Foil Impinged by Array of Free Surface Jets

Abstract The present study focuses on the measurement of the local heat transfer distribution of a smooth flat plate impinged by an array of free surface jets on a thin metal foil. Local Nusselt number distributions are measured for a fixed jet diameter (d = 3 mm). The jet arrays consist of perfectly round apertures arranged in a square pattern, with a uniform spacing of 4d between adjacent jets in both the streamwise and spanwise direction. A wide range of Reynolds numbers varying from 1000 to 12500 are covered in this study. The nozzle to plate spacing (z/d) is varied between 1 to 10. The effect of the Reynolds number and nozzle to plate spacing on the local and spanwise average Nusselt number distributions are studied. The local Nusselt number exhibits an increase with nozzle-to-plate spacing within the low Reynolds number range (Re = 1000 to 2500). However, for Reynolds numbers exceeding 2500, the influence of nozzle-to-plate spacing on Nusselt number distributions remains negligible up to a nozzle-to-plate distance (z/d) of 5. Beyond this point, there is a gradual decrease in the Nusselt number value. The Nusselt number value gradually decreases beyond z/d of 5. At a Reynolds number of 1500, the Nusselt number increases by 71% for z/d = 10 in comparison to z/d = 1. Empirical correlations for local and spanwise average Nusselt number are proposed which satisfactory predict the local as well as spanwise average Nusselt number distributions.

Hydraulic characterization and start-up of a novel circulating flow bio-carriers

High-quality biofilm carriers are crucial for the formation of biofilm, but problems such as slow biofilm growth on the carrier surface have been troubling a large number of researchers. The addition of a carrier changes the flow state in the reactor, which in turn affects the microbial attachment and the quantity of microorganisms. Also, aerobic microorganisms need to use dissolved oxygen in the water to remove water pollutants. In this paper, a novel recirculating flow carrier with a hollow cylinder structure is proposed, with a certain number of hollow inverted circular plates placed at equal distances inside. In this paper, the hydraulic residence time, aeration volume, and the spacing of the inflow plates of the recirculating flow biofilm carrier, which are three important factors affecting the hydraulic characteristics of the reactor, are first investigated. At the same time, it was compared with the common combined carrier to find the optimal operating conditions for the hydraulic characteristics. Secondly, a reactor start-up study was carried out to confirm that the new recirculating flow biofilm carrier could accelerate the biofilm growth by changing the hydraulic characteristics. The results showed that under the same conditions, the hydraulic properties of the reactor were better with the addition of the recirculating flow carrier, with an effective volume ratio of 98% and a significant reduction in short flows and dead zones. The stabilized removal of COD, NH3-N, and TN in the reactor with the addition of the recirculating flow carrier reached about 94%, 99%, and 91% respectively, at the beginning of the 15th day, which effectively proved the feasibility of the recirculating flow carrier.

Heat Transfer Enhancement of Impinging Jet-Corrugated Solar Air Heaters

Abstract Solar air heater (SAH) is one of many applications of solar energy, but it has low thermal performance. To cater to this issue, a novel corrugated jet-impinging channel has been proposed for the absorbing plate of SAHs. The Nusselt number, pressure loss pumping power, and friction factor were computed by experimental and numerical studies for three different arrangements of jets, i.e., 1 × 1 square, 2 × 2, and 3 × 3 jet array with three target plates, i.e., smooth, trapezoidal, and sinusoidal corrugated plates over the Reynolds number range of 1740–2700 and jet-to-target plate spacing of 5.1–14.6. It was observed that jet-to-target plate distance and multiple jets impinging can affect the heat transfer enhancement significantly. An optimization study has been performed using the statistical Taguchi method. The optimum value of Nusselt number was found for the trapezoidal corrugated target plate, with 3 × 3 multiple jet impingement, jet-to-target plate distance of 5.1, and Reynolds number value of 2700, while the optimum value of friction factor was found for 3 × 3 jet impingement. Computational fluid dynamics (CFD) and experimental data are found to be in good agreement. An increase of 11 times was observed in the thermal performance factor as compared to the base case. Trapezoidal corrugation seems to be the effective profile for SAHs.

Study on P-a-Si:H properties of N-type heterogeneous junction solar cells manufactured by large-area parallel plate PECVD machine

P-type hydrogenated amorphous silicon (P-a-Si:H) plays an important role in heterojunction solar cells. On the one hand, P-a-Si:H processed by plasma enhanced vapor deposition (PECVD) can selectively collect carrier holes on the rear of N-type silicon based heterojunctions with intrinsic thin layer (HJT) solar cells (in this article, the back ride of the cell is P-a-Si:H); On the other hand, the ohmic contact between P-a-Si:H and conductive ITO film is beneficial for hole transport. Therefore, the performance of P-a-Si:H has very significant impact on the property of HJT solar cells. The electrical conductivity, impurity activation energy, and passivation performance of silicon wafer surface are the core performance indicators of P-a-Si:H materials themselves. In this paper, we systematically research the optimal RF power density, doping concentration (diborane doped), hydrogen dilution ratio and plate spacing for the growth process of P-a-Si:H using a self-developed large-area parallel plate PECVD equipment (Jincheng Machine). The results show that the P-a-Si:H has an electrical conductivity of 1.27 × 10−3 S/cm and an activation energy of 251 meV, and the maximum mass production efficiency of the HJT solar cell is 25.21%, Voc is 741 mV and Jsc is 41.57 mA/cm2.

Three-Dimensional Electrochemical Oxidation System with RuO2-IrO2/Ti as the Anode for Ammonia Wastewater Treatment

In this study, a three-dimensional electrochemical oxidation system was constructed to treat ammonia nitrogen wastewater generated from the tail gas absorption of a methionine producer by using a homemade MAC mixed with a GAC at a mass ratio of 1:2 as the particle electrode, with a RuO2-IrO2/Ti polar plate as the anode and a stainless steel plate as the cathode. The effects of current density, initial pH value of wastewater, plate spacing, NaCl concentration and particle filling amount on CODCr and NH4+-N removal were investigated through single-factor experiments, and the removal pathways of CODCr and NH4+-N under the system were initially explored via cyclic voltammetry curves, scanning electron microscopy and tertiary butanol quenching experiments. The experimental results showed that the average removal rate of CODCr was 91.03% and that of NH4+-N was 98.89% after electrolysis for 5 h under the conditions of a current density of 40 mA/cm2, no pH adjustment, the spacing of the electrode plates of 8 cm, the NaCl dosing concentration of 1 g/L, and the particle filling amount of 400 g/L. Under this experimental condition, the removal of CODCr occurred mainly through the indirect oxidation of active chlorine and ·OH, and the removal of NH4+-N mainly through the indirect oxidation of active chlorine.

Preparation, Microstructure and Thermal Properties of Aligned Mesophase Pitch-Based Carbon Fiber Interface Materials by an Electrostatic Flocking Method.

The mesophase pitch-based carbon fiber interface material (TIM) with a vertical array was prepared by using mesophase pitch-based short-cut fibers (MPCFs) and 3016 epoxy resin as raw materials and carbon nanotubes (CNTs) as additives through electrostatic flocking and resin pouring molding process. The microstructure and thermal properties of the interface were analyzed by using a scanning electron microscope (SEM), laser thermal conductivity and thermal infrared imaging methods. The results indicate that the plate spacing and fusing voltage have a significant impact on the orientation of the arrays formed by mesophase pitch-based carbon fibers. While the orientation of the carbon fiber array has a minimal impact on the shore hardness of TIM, it does have a direct influence on its thermal conductivity. At a flocking voltage of 20 kV and plate spacing of 12 cm, the interface material exhibited an optimal thermal conductivity of 24.47 W/(m·K), shore hardness of 42 A and carbon fiber filling rate of 6.30 wt%. By incorporating 2% carbon nanotubes (CNTs) into the epoxy matrix, the interface material achieves a thermal conductivity of 28.97 W/(m·K) at a flocking voltage of 30 kV and plate spacing of 10 cm. This represents a 52.1% increase in thermal conductivity compared to the material without TIM. The material achieves temperature uniformity within 10 s at the same heat source temperatures, which indicates a good application prospect in IC packaging and electronic heat dissipation.

Flexural behavior and load-bearing capacity calculation methodology for wooden beams strengthened using aluminum plates attached with self-tapping screws

ABSTRACT To investigate the flexural failure mode and behavior of wooden beams strengthened using aluminum (Al) plates, which were attached with self-tapping screws and structural adhesive, ten specimens were tested in bending. The experimental parameters were the thickness of the bottom Al plate, the longitudinal and transverse grain spacing of the self-tapping screws. The experimental results revealed that (1) compared with unreinforced beams, the reinforced beams exhibited ultimate load capacity and displacement ductility coefficients that were 18.4%–54.3% and 6.4%–43.1% higher, respectively; (2) for the same Al plate thickness in the tensioned area, the initial stiffness of the reinforced wooden beams increases as the longitudinal grain spacing of the screw grains decreases; (3) the plane-section assumption was satisfied by the strain in the middle section of the Al plate-reinforced wooden beam along the height; (4) the strains at the same position in the wooden beam and Al plate were similar, thus indicating that the wooden beam and Al plate behaved collectively. Furthermore, a formula was proposed for calculating the flexural capacity of an Al plate-reinforced wooden beam, thus providing a valuable reference when designing wooden beam reinforcements.

Application of passive autocatalytic recombiners for hydrogen mitigation: 2D numerical modeling and experimental validation

The widespread production and use of hydrogen (H2) requires safe handling due to its wide range of flammability and low ignition energy. In confined and semi-confined areas, a H2 leak creates potential for accumulation of flammable gases. A Passive Autocatalytic Recombiner (PAR) is a safety device for preventing H2 accumulation. PAR is equipped with catalyst plates that assist the activation of the H2 recombination with oxygen (O2) at low concentrations. The heat released from the reaction decreases the gas density, creating a self-sustained natural convective flow, continuously supplying the catalyst surface with H2 present in the air surrounding the PAR. In this study, a 2D numerical model is developed to simulate PAR operation. The model is used to analyze surface reactions, forced versus natural convective flow, plate spacing, heat losses, hydrogen recombination rates, carbon monoxide (CO) poisoning and their influence on the catalyst performance. Experimental data are used for model calibration and validation, showing good agreement for different conditions. The model shows that H2 is almost entirely recombined whereas CO is only partially recombined. Natural and forced convection flows result in similar velocity profiles and large plate spacing produces higher temperatures, higher velocities but lower H2 conversion. Moreover, the model shows a new feature for simulating CO poisoning via surface reactions. Overall, the model provided novel insights into PAR operation, showing the importance of surface reactions and it will be useful to assess design aspects and the effectiveness of PARs for H2 mitigation.

Impact of stack length on performance of standing wave thermoacoustic refrigerator

The low coefficient of performance of thermoacoustic refrigerators has limited their development. The goal of this paper is to investigate the effect of different stack lengths on standing wave thermoacoustic refrigerator (TAR) performance. The stack is essential in TAR because it expands the gas-solid interface, allowing for a greater temperature difference between the warm and cold regions. Hence literature studies on stack length, geometry, plate spacing, and material have been investigated. A quantitative analysis was performed to determine an effective TAR design by numerically modelling three geometries using COMSOL Multiphysics 6.0. A quarter wavelength resonator tube was designed using a 2D axisymmetric model. The acoustic wave and energy fields in solids were studied using conjugate heat transfer, with the fluid flow considered laminar and helium as the working gas. The optimal TAR design was chosen based on the lowest temperature difference between the three simulated geometries. Seven numerical models were simulated for stack lengths ranging from 15 mm to 45 mm, revealing that COP increased as stack length decreased, while the temperature difference decreased.