Multiple Jet Impingement Research Articles

Numerical study of heat transfer and entropy generation in ribbed microchannel with nanofluid and multiple jet impingement

Due to the high miniaturization of electronic devices, there is an urgent need to eliminate high heat flux in electronic devices and improve their heat transfer characteristics. This article simulated the single-phase flow to study the effects of five different arrangements of column ribs and different volume concentration (1 %–5%) of nanofluids on the convective heat transfer coefficient, pressure drop, and the irreversibility of flow heat transfer in ribbed microchannel heat sinks with multiple jets impingement (MJI) within the Re range of 200–1000. The working coolants is deionized water and water - Al2O3 nanofluid. Different important parameters, such as the characteristic of heat transfer and flow, Performance Evaluation Criterion (PEC), and entropy generation are investigated. The results indicated that MJI III can effectively improve the convective heat transfer coefficient while the increase in pressure drop is not obvious. The PEC of MJI III is 1.408 at Re = 600, which is much higher than the other MJIs. Additionally, the cooling performance and irreversibility of water-Al2O3 nanofluid are superior to those of deionized water within the research scope. With the concentration, the irreversibility of flow and heat transfer of water-Al2O3 nanofluid increasing increases. The data shows that, the overall performance is optimal when φ = 1 %, and its highest PEC is 1.75 at Re = 400.

Flow and heat transfer analysis of submerged multiple synthetic jet impingement in a square channel with forced-flow

This study experimentally and numerically investigated the flow and heat transfer of submerged multiple synthetic jet impingement in forced crossflow in a square-section channel with a constant heat flux on the bottom surface. In the forced channel flow, effects on heat transfer of six synthetic jets placed diagonally in the main flow have four different amplitudes and six different frequencies at various Reynolds numbers (6000 ≤ Re ≤ 40000) were examined. Jets were submerged vertically into the main flow and their effects on heat transfer in the turbulent regime of the main flow were analyzed. Temperature measurements were made using thermocouples placed at the channel entrances and exits on the target surface. The Nusselt numbers (Nu) were calculated using the measured temperatures. The results indicate that at Re = 6000, the target surface temperature decreases significantly with increasing amplitude and frequency, and the effects of amplitude and frequency on surface temperatures decreased at increasing Reynolds numbers. It was observed that the THP values increased with increasing amplitude and frequency for all Reynolds numbers tested. For a constant jet parameter (Ao = 0.88 and Wo = 27), the highest THP was determined as 2.06 at Re = 6000.

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.

Thermal Performance Factor of Impinging Jet‐Angled Corrugated Solar Air Heaters

Solar energy is a clean and sustainable source of power generation. There are various industrial and domestic applications of Solar Air Heaters (SAHs), but their low thermal efficiency poses a challenge. To improve thermal efficiency, a novel‐angled corrugated jet‐impinging channel has been proposed for the absorbing plate of SAHs. A numerical study has been performed for four different arrangements of jets, i.e., single circular, single square, 2 × 2 square, and 3 × 3 square jet array with four channels, i.e., 30°, 45°, 60°, and 90° corrugated over the Reynolds number range of 1600–2700 for the jet to target plate range of 4.9–15. It is observed that multiple jets impinging increases the heat transfer significantly. The optimization has been performed by instigating the parametric study. Flow and thermal profiles are studied. The 45° corrugated target plate with 3 × 3 multiple jet impingement, 4.9 jet‐to‐target plate distance, and 2700 Reynolds number is chosen to have the best thermal efficiency. A Thermal Performance Factor of around 8 was achieved as compared to the base case.

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.

DNS analysis of the effect of control parameters on the heat transfer performance of intermittently controlled impinging jets

Impinging jets are used industrially in various applications such as heating and cooling. However, multiple impinging jets (MIJ) create a complex flow field due to interference between the individual jets, which hinders heat transfer. In order to solve the problem of heat transfer performance in MIJ, a new control method must be developed. This study introduces intermittent control to 13 hexagonally arranged circular jets to investigate the possibility of control. In the intermittent control, the 13 jets are divided into three groups, and each group is intermittently issued. The distance between jets and the issuing period are changed as control parameters, and the heat transfer characteristics are evaluated using direct numerical simulation (DNS). The time-averaged velocity field revealed the effects of the intermittent period and the distance between jets on the flow characteristics, and the Nusselt number distribution on the wall surface indicated that the proposed method improves the heat transfer characteristics.

Conductive panel cooling by using coupled effects of nano-jet impingement, double rotating cylinders and magnetic field under cross-flow

Purpose This study aims to examine the effects of cross-flow and multiple jet impingement on conductive panel cooling performance when subjected to uniform magnetic field effects. The cooling system has double rotating cylinders. Design/methodology/approach Cross-flow ratios (CFR) ranging from 0.1 to 1, magnetic field strength (Ha) ranging from 0 to 50 and cylinder rotation speed (Rew) ranging from −5,000 to 5,000 are the relevant parameters that are included in the numerical analysis. Finite element method is used as solution technique. Radial basis networks are used for the prediction of average Nusselt number (Nu), average surface temperature of the panel and temperature uniformity effects when varying the impacts of cross-flow, magnetic field and rotations of the double cylinder in the cooling channel. Findings The effect of CFR on cooling efficiency and temperature uniformity is favorable. By raising the CFR to the highest value under the magnetic field, the average Nu can rise by up to 18.6%, while the temperature drop and temperature difference are obtained as 1.87°C and 3.72°C. Without cylinders, magnetic field improves the cooling performance, while average Nu increases to 4.5% and 8.8% at CR = 0.1 and CR = 1, respectively. When the magnetic field is the strongest with cylinders in channel at CFR = 1, temperature difference (ΔT) is obtained as 2.5 °C. The rotational impacts on thermal performance are more significant when the cross-flow effects are weak (CFR = 0.1) compared to when they are substantial (CFR = 1). Cases without a cylinder have the worst performance for both weak and severe cross-flow effects, whereas using two rotating cylinders increases cooling performance and temperature uniformity for the conductive panel. The average surface temperature lowers by 1.2°C at CFR = 0.1 and 0.5°C at CFR = 1 when the worst and best situations are compared. Originality/value The outcomes are relevant in the design and optimization-based studies for electric cooling, photo-voltaic cooling and battery thermal management.

Prediction of Mean Heat Transfer Characteristics of Multiple Impinging Jets with Steady RANS Simulation Using a Coarse Mesh

The capability of the standard SST k-ω turbulence model for the prediction of jet impingement cooling characteristics using a coarse mesh is investigated. The discussion is based on a sensitivity study with five computational grids, differing from each other in topology and resolution. The analysis considers a hexagonal configuration of turbulent jets at the inlet Reynolds number equal to 20,000, with the distance between the nozzle and target plates equal to four nozzle diameters. The results of steady RANS simulations are validated against the time-averaged LES results and data from experiments. The mean heat transfer characteristics of turbulent impinging jets have been successfully reproduced with all tested grids, which indicates that for a rather accurate mean heat transfer prediction, it is not necessary to resolve all the small-scale flow features of impinging jets above the target plate.

Three dimensional numerical study of PV module cooling by using thermoelectric effects and nano-enhanced confined multiple slot jet impingement

In this study, 3D numerical study of photovoltaic (PV) module cooling is analyzed by combined utilization of thermoelectric generator (TEG) and nano-enhanced slot jet impingement system. For the relevant parameters of interest, such as Reynolds number (between 10 and 100), nanoparticle loading (solid volume fraction between 0 and 0.02), non-dimensional vertical distance between the slots and upper plate (between 2.5 and 8), non-dimensional spacing between the slots (between 2.5 and 8), and cold NF inlet temperature (between 20oC and 30oC), finite element method is utilized. Using only TEG and nano-jet assisted cooling with TEG result in PV-cell temperature reduction by about 43.33oC and 69.55oC as compared to un-cooled PV module. It is observed that cell temperature decreases by about 2.4oC-2.9oC when considering the minimum and maximum Reynolds number cases. When nanoparticle loading is increased to 0.02, output TEG power rises while cell temperature decreases by about 0.75oC. When varying the vertical distance between the slot to the impinging surface, cell temperature changes up to 1.9oC while distance between the slots has very slight impact on the temperature variation. Decreasing the inlet fluid temperature by about 10oC decreases the cell temperature by about 8.5oC.

Flow dynamics and heat transfer characterization of confined multiple jets impinging on a complex surface

Submerged and confined multiple jet impingement is widely implemented in cooling applications since it provides high heat transfer coefficients and uniformity over the target plate. Its performance depends on several variables that make it complex and difficult to control. To understand the physical phenomena and characterize the flow field, an in-depth study, using Particle Image Velocimetry (PIV) technique and an heat flux sensor, is conducted in this study. The PIV provides relevant data, but the accuracy of the measurements depends on an effective experimental setup and a careful selection of the most appropriate tracer particles. Therefore, this work presents the purpose-built experimental apparatus and comprises an analysis of the efficiency of different seeding particles. The results demonstrate that olive oil particles are appropriate to track turbulent flows since particles with about 1 μm diameter are obtained by the seeding generator. PIV measurements highlight the complexity of the jet flow impinging on a step surface, which induces a strong flow reversal that affects the jet flow development and the interaction with the adjacent jets. The large-scale structures induced in the vicinity of the target plate are captured by the PIV, as well as the strong fountain flows generated between the adjacent jets. Compared with the flat geometry, the turbulence intensity at the central jet is around 25% higher for the 1 D step, while for the 2 D step, this increase reaches 7.5%. The increased turbulence intensity leads to an heat transfer enhancement. For the 2 D step plate, the Nusselt number recorded is 25% greater than the flat plate. Through this study, relevant insights for several engineering applications that use multiple jet impingement are provided, highlighting that the combination of PIV and heat flux sensors are appropriate to characterize the jet’s flow dynamics and the heat transfer of this complex process.

Effects of elasticity and waviness of the conductive panel surface on the cooling performance and entropy generation by using nano-enhanced multiple impinging jets

The design of cooling systems is crucial for the thermal management of many energy systems including batteries, microelectro-mechanical systems, photovoltaics and many others. In this study, cooling system for elastic curved conductive panel is developed by using nano-enhanced multiple jet impingement. ALE finite element modeling of the entire coupled fluid-structure conjugate heat transfer system is employed for assessment, which considers both elastic flat and wavy panels. Type of the panel and operating parameters affect the cooling performance and entropy generation. Different effects and contributions of varying parameters such as Cauchy number (Ca), jet-cooling spacing (to the target plate and between the slots), wave amplitude and number of the conducive panel and nanoparticle loading amount in the pure fluid on the cooling performance and entropy generation features are analyzed. Increases in the Cauchy number, waveform amplitude, slot-slot distance, and slot-plate distance reduce the effectiveness of cooling, whereas increases in the nanoparticle loading have the reverse effect. When varying the Ca, there is 12.1% decrease of average Nusselt number (Nu) while average panel temperature rise becomes 3.1°C by using nanofluid. The average Nu deteriorates by 7.7% and 6.6% when amplitude and wave number are varied while the corresponding temperature rises are achieved as 1.4°C and 1°C. When wavy and flat surfaces are used, using nanofluid provides 2.8°C and 2.5°C temperature drops. Lower entropy generation (EG) is obtained with flexible panel while higher amplitude of the wave form and increasing the nanoparticle amount result in EG reduction. The amount of EG reduction by using nanofluid becomes 21% and 27% at the highest loading.

Effect of Rib Blockage Ratio and Arrangements on Impingement Heat Transfer in Double-Wall Cooling

Abstract A numerical study was conducted on the multiple jet impingement heat transfer of the double-wall cooling with high blockage ratio ribs of various configurations. Three different blockage ratios (BR = 0.2, 0.3, and 0.5) and two rib arrangements relative to the effusion holes (l/Sx = 0.25 and 0.75) were thoroughly examined using the RANS method with the SST–KIC turbulence model, considering the Kato–Launder modification (K), intermittency (I), and crossflow (C) transition effects. The ratio of jet-to-target plate spacing to jet diameter (H/d) was fixed to be 1, and Reynolds numbers varied in the range of 4000–16,000. Furthermore, the computed data on the rib roughed wall were also compared with those on a flat plate for the double-wall cooling. The results demonstrate that the installation of the high blockage ribs significantly decreases the detrimental crossflow effect due to the blockage effect of the ribs and intensively disturbs the jet flow in flow passing over the ribs, thereby enhancing the heat transfer performance. For the impingement/effusion cooling, the arrangement of the rib downstream of the effusion holes (l/Sx = 0.25) shows more advantages, and the heat transfer level rises quickly as BR increases. The best thermal-hydraulic performance and heat transfer uniformity on the rib roughed target plate is both obtained at BR = 0.3, which can be increased by up to 10% and 8%, respectively, compared to those on the flat plate.

Flow and heat transfer in rotating smooth and ribbed multi-channel double-wall structure with multiple-jet impingement cooling

In this study, the heat transfer of multiple-jet impingement in rotating smooth and ribbed multichannel double-wall cooling structure with film extraction are investigated. The dimensionless jet-to-target spacing is 1, and the dimensionless jet-to-jet spacing is 3.55. In ribbed channel, the rib height is 1 mm and rib spacing is 8 mm. The experimental jet Reynolds number ranges from 2000 to 8000, and the maximum jet rotation number is 0.22. The test section contains five impingement channels. The local average convective heat transfer coefficient is measured by the “copper plate method”. The SST k-ω model is used to study the effect of rotation on the flow in channels. The results show that the heat transfer gap between high and low radius is more evident with an increase of the Roj. This is because the rotation effect increases and decreases the mass flow rate at high and low radius, respectively. Moreover, rotation can strengthen the impingement effect of the trailing side (TS) while weakening the effect of the leading side (LS) when the Roj is less than 0.06, Which causes differences in the heat transfer between the LS and TS of the impingement channel. Furthermore, affected by the ribs, the average heat transfer of ribbed target surface is improved. The area of high heat transfer region generated by impingement decreases, and an inverted butterfly-shaped high heat transfer region is generated near the film hole. Finally, the rib weakens the effect of rotation on the flow of target surface to some extent.

Experimental and Numerical Investigation of Flow Structure and Heat Transfer Behavior of Multiple Jet Impingement Using MgO-Water Nanofluids.

Nanofluids have attracted significant attention from researchers due to their ability to significantly enhance heat transfer, especially in jet impingement flows, which can improve their cooling performance. However, there is a lack of research on the use of nanofluids in multiple jet impingements, both in terms of experimental and numerical studies. Therefore, further investigation is necessary to fully understand the potential benefits and limitations of using nanofluids in this type of cooling system. Thus, an experimental and numerical investigation was performed to study the flow structure and heat transfer behavior of multiple jet impingement using MgO-water nanofluids with a 3 × 3 inline jet array at a nozzle-to-plate distance of 3 mm. The jet spacing was set to 3, 4.5, and 6 mm; the Reynolds number varies from 1000 to 10,000; and the particle volume fraction ranges from 0% to 0.15%. A 3D numerical analysis using ANSYS Fluent with SST k-ω turbulent model was presented. The single-phase model is adopted to predict the thermal physical nanofluid. The flow field and temperature distribution were investigated. Experimental results show that a nanofluid can provide a heat transfer enhancement at a small jet-to-jet spacing using a high particle volume fraction under a low Reynolds number; otherwise, an adverse effect on heat transfer may occur. The numerical results show that the single-phase model can predict the heat transfer trend of multiple jet impingement using nanofluids correctly but with significant deviation from experimental results because it cannot capture the effect of nanoparticles.

Local heat transfer characteristics of circular multiple air jet impinging on a semicircular concave surface

ABSTRACT The local heat transfer characteristics of circular multiple air jet impingement on semicircular concave surface were studied experimentally. For constant Reynolds number (Re = 9,000), the effect of jet to concave surface spacing (z/d = 1, 4.2, 6), ratio of curvature (D/d = 4.28, 6, 8.6), jet-to-jet spacing (s/d = 2.4, 4, 5.6), and number of jets were considered. The local heat transfer characteristics were determined by using infrared thermal camera and thin foil method. Lower curvature value ratio (D/d = 4.28) resulted higher average heat transfer coefficient due to broader spread of heat transfer distribution, whereas higher curvature ratio (D/d = 8.6) resulted in lower average heat transfer coefficient due to steeper heat transfer distribution in the stagnation area. At lower D/d, z/d, and s/d with seven jet configuration, the heat transfer coefficients were found effective as compared to other configurations due to broad heat transfer distribution and less interaction between the jets. At given D/d and s/d configuration, the stagnation Nu at θ = 0° do not coincide with jet hole center axis and this shift is more pronounced at higher z/d value. This could be due to additional push before jet impinging on concave surface. The secondary peaks were observed between two neighboring stagnation regions in Nu distribution along the center longitudinal line for lower z/d and higher s/d values. This resulted due to upwash that was obtained from jet interactions related to collisions with the wall jets. The correlations of stagnation line average Nu and overall average Nu were obtained. The coefficient of variance of local heat transfer coefficient for each configuration was determined, and correlation was proposed to analyze the degree of non-uniformity.

Effect of jet plate thickness on the local heat transfer coefficient with multiple air jet impingement

For designing a multiple jet impingement cooling system, the thickness of jet plate (a passage through which jet comes out) is one of the important parameters. Considering the thermal point of view, the thickness of the plate should be chosen so that it would enhance the heat transfer rate. In this study, the effect of jet plate thickness on the local heat transfer coefficient on a flat plate with multiple impinging air jets is investigated. The thickness ratios (t/d) of 0.5, 1.0 and 2.67 are studied. Reynolds number is varied from 5000 to 20,000 and jet-to-plate distance (z/d) is varied from 1 to 5. Jet diameter (d) is chosen to be 6 mm. The jet-to-jet distance (p/d) is kept constant at 3.Steady-state thin metal foil technique, along with infrared thermography, is used to obtain the temperature distribution and thereby the heat transfer coefficient. Coefficient of discharge for each jet plate, central line velocity decay and pressure distribution on the target surface are measured. These measurements provided new insights to better understand the heat transfer results in this study. For lower jet-to-plate distances (t/d = 0.5 to 1), heat transfer decreases with the increase in the jet plate thickness ratio. However, heat transfer is not affected with the further increase in the jet plate thickness ratio i.e., t/d = 1 to 2.67. Therefore, smaller jet plate thickness ratio is suitable to obtained high heat transfer rate. This study presents a new correlation for the local Nusselt number distribution or different jet plate thickness.

Impacts of using discrete and continuous porous layers on the cooling performance of confined multiple slot jet impingement under partially active magnetic field

PurposeThe purpose of this study is to examine the effects of using discrete and continuous porous layers on the convective heat transfer improvement for multiple slot jet impingement onto a flat surface under magnetic field.Design/methodology/approachIn the domains which are separated by the porous layers, uniform magnetic field with different strengths is used and as the solution technique finite element method is used. The numerical study is conducted considering different values of parameters: Reynolds number (250–1000), strength of magnetic field in different domains (Hartmann number between 0 and 20), permeability of discrete or continuous layers (Darcy number between 105 and 102) and number of layers in discrete case (2–10). Artificial neural network is used for performance estimation of systems equipped with different types of porous layers.FindingsIt is observed that significant differences occur in the local Nu between the discrete and continuous layer case, especially at lower Re, while peak Nu value is 77% higher in discrete layer configurations as compared to continuous one at Re = 250. Upper domain magnetic field results in average Nu enhancement, while the trend is opposite for the lower domain magnetic field strength. The increment amount becomes 10%, while the reduction amount is obtained as 38% at the highest magnetic field strengths. The permeability of layers in both cases and number of layers in discrete porous layer case provide effective solution for the cooling performance control. A modeling approach based on artificial neural networks provides fast thermal performance estimations of multiple impinging jets equipped with discrete and continuous porous layers.Originality/valueOutcomes of the study are useful in development and optimization of new cooling systems in many thermal engineering systems encountered in photovoltaic panels, micro-electro-mechanical systems, metal processing and many others.

Heat Transfer Enhancement in Tubular Heat Exchanger with Jet Impingement: A Review

Heat exchanger (HE) is a thermal device used to transfer heat from higher fluid temperatures to lower fluid temperatures. There is an increasing need to increase the efficiency of HEs, develop a wide range of investigations to increase heat transfer rate (HTR), and reduce the size and cost of industrial apparatus in accordance. The current work's goal is to review articles that discuss the main types of tubular heat HEs, factors that affect HTR, and jet impingement in tubular HEs, which are considered among the equipment used in various industries. Researchers have proposed several models of tubular HEs. Many industrial processes, cooling technology, refrigeration equipment, sustainable energy applications, and other fields use tubular HEs. Jet impingement cooling is assumed to be a very efficient method for increasing HT rate, and it has many uses in both the scientific and industrial spheres. This paper's goal is to present an overview of various techniques for improving HT in relation to jet impingement cooling and to define the area of potential future research. This study focuses on a variety of experimental and numerical studies to examine the HT and hydrodynamic behaviour of jet impingement over a range of Reynolds numbers, target surface shapes, distances from the jet plate or nozzle to the target plate, extended jet holes, and the use of nanofluids. Both single jet and multiple jet impingements cooling are included in the current work. The summary of jet impingement for various applications keeps the spotlight on new methods for enhancing HT.

Effect of arc-shaped twisted-baffles on augmented heat transfer in a rectangular duct

In this current work, the effect of utilizing arc-shaped twisted-baffles (T-ABs) in a rectangular air channel on thermal performance factor (TPF) has been experimentally studied. In these experiments, the influence of the changes in parameters such as dimensions of pitch ratio (p/w), attached arc-shape angle (α), and Reynolds number (Re) are explored. The comparisons demonstrate that a channel mounted with arc-shaped twisted-baffles yielded considerably greater Nusselt numbers than a smooth channel, possibly attributable to multiple-impinging jets near the channel surface. Heat transfer enhancements of twisted arc-shaped baffles (T-AB) having larger attack angles were superior to those having smaller attack angles. The one with α = 90o offered greater heat transfer rates than the ones with α = 20o, 40o, 60o, and 80o by approximately 8%, 7%, 4%, and 2%, respectively. The superior heat transfer was attributed to the better contact between the working fluid and heat transfer surfaces. In addition, utilizing arc-shaped twisted-baffles with the lowest p/w of 4.0, in a channel produced stronger vortices and multiple impinging jets, which caused better fluid mixing than other p/w. The optimum condition is achieved using T-ABs at an attached arc-shape angle of α = 90o, p/w = 4.0 and Re = 4000, where the heat transfer rate (Nu), friction factor (f) and TPF are found to be, respectively, 3.31, 4.68 and 1.98 times greater than those of a plain channel.

Improving the Cooling Performance in a Low Reynolds Duct Flow of Multiple Impinging Jets with Non-uniform Spacing and Unequal Diameters of Nozzles

Improving the Cooling Performance in a Low Reynolds Duct Flow of Multiple Impinging Jets with Non-uniform Spacing and Unequal Diameters of Nozzles