scholarly journals Heat Transfer Augmentation through Different Jet Impingement Techniques: A State-of-the-Art Review

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6458
Author(s):  
Liaqat Hussain ◽  
Muhammad Mahabat Khan ◽  
Manzar Masud ◽  
Fawad Ahmed ◽  
Zabdur Rehman ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Phase Change Materials ◽  
Jet Impingement ◽  
Target Surface ◽  
Industrial Applications ◽  
Heat Transfer Augmentation ◽  
Numerical Studies ◽  
Single Jet ◽  
Jet Nozzle ◽  
Future Work

Jet impingement is considered to be an effective technique to enhance the heat transfer rate, and it finds many applications in the scientific and industrial horizons. The objective of this paper is to summarize heat transfer enhancement through different jet impingement methods and provide a platform for identifying the scope for future work. This study reviews various experimental and numerical studies of jet impingement methods for thermal-hydraulic improvement of heat transfer surfaces. The jet impingement methods considered in the present work include shapes of the target surface, the jet/nozzle–target surface distance, extended jet holes, nanofluids, and the use of phase change materials (PCMs). The present work also includes both single-jet and multiple-jet impingement studies for different industrial applications.

Numerical Study of Flow and Heat Transfer of Impingement Cooling on Model of Turbine Blade Leading Edge

2010 ◽  
Author(s):  
Zhao Liu ◽  
Zhenping Feng ◽  
Liming Song
Keyword(s):  
Heat Transfer ◽  
Turbine Blade ◽  
Numerical Study ◽  
Leading Edge ◽  
Jet Impingement ◽  
Target Surface ◽  
Nozzle Diameter ◽  
Impingement Cooling ◽  
Jet Nozzle ◽  
Blade Leading Edge

In this paper a numerical simulation is performed to simulate the impingement cooling on internal leading edge region, which is stretched by the middle cross section of the first stage rotor blade of GE-E3 engine high pressure turbine, and in the condition that jets flow is ejected from a row of four different diameter circular nozzles. The relative performances of three versions of turbulence models including the RNG κ-ε model, the standard κ-ω model and the SST κ-ω model in the simulation of a row of circle jet impingement heat transfer are compared with available experimental data. The results show that SST κ-ω model is the best one based on simulation accuracy. Then the SST κ-ω model is adopted for the simulation. The grid independence study is also carried out by using the Richardson extrapolation method. A single array of circle jets is arranged to investigate the impingement cooling and its effectiveness. Four different jet nozzle diameters are studied and seven different inlet flow Mach numbers of each jet nozzle diameter are calculated. The influence of the ratio of the spacing of jet nozzle from the target surface to the jet nozzle diameter on impingement cooling is also studied, in case of a constant ratio of jet spacing to jet nozzle diameter in different jet nozzle diameters. The results indicate that the heat transfer coefficient on the turbine blade leading edge increases with the increase of jet Mach number and jet nozzle diameter, the spanwise area weight average Nusselt number decreases with the increase of the ratio of the spacing of jet nozzle from the target surface to jet nozzle diameter, and a lower ratio of spacing of jet nozzle from the target surface to the jet nozzle diameter is desirable to improve the performance of impingement cooling on turbine leading edge.

Heat Transfer of Confined Circular Jet Impingement

2001 ◽  
Vol 17 (1) ◽  
pp. 29-38
Author(s):  
Shou-Shing Hsieh ◽  
Jung-Tai Huang ◽  
Huang-Hsiu Tsai
Keyword(s):  
Heat Transfer ◽  
Average Nusselt Number ◽  
Jet Impingement ◽  
Local Heat Transfer ◽  
Target Surface ◽  
Local Heat ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Plate Spacing ◽  
Single Jet

ABSTRACTExperiments for heat transfer characteristics of confined circular single jet impingement were conducted. The effect of jet Reynolds number, jet hole-to-plate spacing and heat flux levels on heat transfer characteristics of the heated target surface was examined and presented. The local heat transfer coefficient along the surface is measured and correlations of the stagnation point, local and average Nusselt number are developed and discussed. Finally, comparisons of the present data with existing results were also made.

scholarly journals Heat Transfer and Flow Characteristics of Circular Jets Impinging on a Horizontal Flat Wall

1997 ◽  
Author(s):  
Shou-Shing Hsieh ◽  
Jung-Tai Huang
Keyword(s):  
Heat Transfer ◽  
Flow Characteristics ◽  
Jet Impingement ◽  
Local Heat Transfer ◽  
Target Surface ◽  
Local Heat ◽  
Plate Spacing ◽  
Fundamental Understanding ◽  
Circular Jets ◽  
Single Jet

An experimental study was performed in a confined circular single jet impingement. The effect of jet Reynolds number, nozzle-to-plate spacing and heat flux levels on heat transfer characteristics of the heated target surface was examined and presented. Flow visualization was made to broaden our fundamental understanding of the physical process of the type of flow. Transition and turbulent regimes are identified. The local heat transfer coefficient along the surface is measured and correlation of the stagnation point Nusselt number are presented and discussed.

Effects of Rotation on Heat Transfer due to Jet Impingement on Cylindrical Dimpled Target Surface

2016 ◽  
Author(s):  
Prashant Singh ◽  
Srinath Ekkad
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Ambient Pressure ◽  
Jet Impingement ◽  
Target Surface ◽  
Diameter Ratio ◽  
Absolute Pressure ◽  
Target Plate ◽  
Heat Transfer Augmentation ◽  
High Heat Transfer

Jet impingement has been extensively used in gas turbine airfoil internal cooling, especially leading edge and mid-chord region, which are subjected to high heat transfer loads. Earlier studies have shown that impingement onto dimpled surface results in higher heat transfer augmentation, particularly in maximum crossflow setting. The present study investigates the effect of Coriolis force and buoyancy in rotating channel featuring round shape jet plate and dimpled target plate, where the spent air is allowed to exit in only one direction, thus imposing maximum crossflow. In order to ensure that the buoyancy acts in a direction similar to actual gas turbine blades, colder air is passed into the feed chamber (also in rotation). Detailed heat transfer measurements are presented using transient liquid crystal thermography, where the target surface is modeled as one-dimensional semi-infinite solid. The jet plate features three (and four) rows of circular holes, where the normalized spanwise and streamwise pitch (x/d, y/d) of jets is kept at 3. The normalized jet-to-target surface distance (z/d) is 4 and the nozzle aspect ratio is 2. The target plate features four rows of dimples, where the dimple print diameter to jet hole diameter ratio is 0.61. The cylindrical dimple arrangement on the target plate has been kept the same for all the configurations tested, where the dimple pitch to dimple print diameter ratio is kept at 1.832. The baseline case for the normalization of Nusselt number is the smooth target surface. Three different configurations of jet plate has been studied. The flow and rotation conditions have been kept the same for all the configurations, where the average Reynolds number (based on jet hole hydraulic diameter: Rej) has been maintained at 2500 and the rotational speed has been kept at 400 RPM (corresponds to Roj of 0.00274). Flow experiments have been carried out to determine the variation of discharge coefficient of each hole with the plenum absolute pressure to ambient pressure ratio, and these Cd measurements were used in the determination of the flow distribution in the jet hole plate. Under non-rotating conditions, dimpled target surface have heat transfer enhancements greater than unity. Also, for non-rotating cases, crossflow effects have been seem to be maximum and for long exit lengths, dimpled target surfaces might have lower heat transfer as compared to smooth target. It has been found that rotation has negative effects on heat transfer augmentation on dimpled target surface for all three configurations studied.

Nanoliquid jet impingement heat transfer for a phase change material (PCM) embedded radial heating system

2021 ◽  
pp. 1-10
Author(s):  
Fatih Selimefendigil ◽  
Hakan F. Oztop
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Phase Change Material ◽  
Jet Impingement ◽  
Target Surface ◽  
Spatial Average ◽  
Average Heat ◽  
Plate Spacing ◽  
Impingement Heat Transfer ◽  
Change Material

Abstract Nanoliquid impingement heat transfer with phase change material (PCM) installed radial system is considered. Study is performed by using finite element method for various values of Reynolds numbers (100 ≤ Re ≤ 300), height of PCM (0.25H ≤ hpcm = 0.7H ≤ 0.75H) and plate spacing (0.15H ≤ hpcm = 0.7H ≤ 0.40H). Different configurations with using water, nanoliquid and nanoliquid+PCM are compared in terms of heat transfer improvement. Thermal performance is improved by using PCM while best performance is achieved with nanoliquid and PCM installed configuration. At Re=100 and Re=300, heat transfer improvements of 26% and 25.5% are achieved with nanoliquid+PCM system as compared to water without PCM. Height of the PCM layer also influences the heat transfer dynamic behavior while there is 12.6% variation in the spatial average heat transfer of the target surface with the lowest and highest PCM height while discharging time increases by about 76.5%. As the spacing between the plates decreases, average heat transfer rises and there is 38% variation.

scholarly journals Numerical heat transfer analysis of micro-scale jet-impingement cooling in a high-pressure turbine vane

2021 ◽  
Author(s):  
Karan Anand
Keyword(s):  
Heat Transfer ◽  
Three Dimensional ◽  
Jet Impingement ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Heat Transfer Analysis ◽  
Transfer Rates ◽  
Numerical Heat Transfer ◽  
Turbine Vane ◽  
Single Jet

This research provides a computational analysis of heat transfer due to micro jet-impingement inside a gas turbine vane. A preliminary-parametric analysis of axisymmetric single jet was reported to better understand micro jet-impingement. In general, it was seen that as the Reynolds number increased the Nusselt number values increased. The jet to target spacing had a considerably lower impact on the heat transfer rates. Around 30% improvement was seen by reducing the diameter to half while changing the shape to an ellipse saw 20.8% improvement in Nusselt value. The numerical investigation was then followed by studying the heat transfer characteristics in a three-dimensional, actual-shaped turbine vane. Effects of jet inclination showed enhanced mixing and secondary heat transfer peaks. The effect of reducing the diameter of the jets to 0.125 mm yielded 55% heat transfer improvements compared to 0.51 mm; the tapering effect also enhanced the local heat transfer values as local velocities at jet exit increased.

The Effect of Entrainment Temperature on Jet Impingement Heat Transfer

1984 ◽  
Vol 106 (1) ◽  
pp. 27-33 ◽  
Author(s):  
S. A. Striegl ◽  
T. E. Diller
Keyword(s):  
Heat Transfer ◽  
Jet Impingement ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Recirculation Region ◽  
Measured Temperature ◽  
Air Jets ◽  
Impingement Heat Transfer ◽  
Single Jet ◽  
Multiple Plane

An experimental study was done to determine the effect of entrainment temperature on the local heat transfer rates to single and multiple, plane, turbulent impinging air jets. To determine the effect of entrainment of the surrounding fluid, the single jet issued into an environment at a temperature which was varied between the initial temperature of the jet and the temperature of the heated impingement plate. An analytical model was used to correlate the measured heat transfer rate to a single jet. The effect of the entrainment temperature in a single jet was then used to analyze the effect of entrainment from the recirculation region between the jets of a jet array. Using the measured temperature in the recirculation region to include the effect of entrainment, the single jet correlations were successfully applied to multiple jets.

Effect of Film Extraction on Impingement Heat Transfer Characteristics of Jet Arrays on Spherical-Dimpled Surfaces

2015 ◽  
Author(s):  
Xing Yang ◽  
Zhao Liu ◽  
Zhenping Feng
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Film Cooling ◽  
Coupling Effect ◽  
Jet Impingement ◽  
Local Heat Transfer ◽  
Target Surface ◽  
Local Heat ◽  
Separation Distance ◽  
Plate Spacing

Detailed heat transfer distributions are numerically investigated on a multiple jet impingement target surface with staggered arrays of spherical dimples where coolant can be extracted through film holes for external film cooling. The three dimensional Reynolds-averaged Navier-Stokes analysis with SST k-ω turbulence model is conducted at jet Reynolds number from 15,000 to 35,000. The separation distance between the jet plate and the target surface varies from 3 to 5 jet diameters and two jet-induced crossflow schemes are included to be referred as large and small crossflow at one and two opposite exit openings correspondingly. Flow and heat transfer results for the dimpled target plate with three suction ratios of 2.5%, 5.0% and 12.0% are compared with those on dimpled surfaces without film holes. The results indicate the presence of film holes could alter the local heat transfer distributions, especially near the channel outlets where the crossflow level is the highest. The heat transfer enhancements by applying film holes to the dimpled surfaces is improved to different degrees at various suction ratios, and the enhancements depend on the coupling effect of impingement and channel flow, which is relevant to jet Reynolds number, jet-to-plate spacing and crossflow scheme.

Sign in / Sign up

Export Citation Format

Share Document