The boundary layer equations for plane, incompressible, and steady flow are 

$$\matrix{ {u{{\partial u} \over {\partial x}} + v{{\partial u} \over {\partial y}} = - {1 \over \varrho }{{\partial p} \over {\partial x}} + v{{{\partial ^2}u} \over {\partial {y^2}}},} \cr {0 = {{\partial p} \over {\partial y}},} \cr {{{\partial u} \over {\partial x}} + {{\partial v} \over {\partial y}} = 0.} \cr }$$

Boundary Layer Theory

In response to recent advances in numerical heat transfer research, the K-8 Committee of Theory and Fundamental Research of the ASME Heat Transfer Division has sponsored a symposium on the subject at the 1990 AIAA/ASME Thermophysics and Heat Transfer Conference in Seattle, Washington. This symposium volume contains the papers presented in three technical sessions. Works dealing with both the methodology and the results of numerical solutions of heat transfer problems are included in this volume. A large number of excellent manuscripts were submitted by researchers from this country and abroad. The papers collected here provide a representative cross section of current contributions to numerical methods in heat transfer.

Numerical heat transfer

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Effects of Heat Treatment System on Mechanical Strength and Crystallinity of CaO-MgO- Al2O3-SiO2 Glass-Ceramics Containing Coal Gangue and Iron Ore Tailings

A numerical simulation for heat exchanger with continuous helical baffles was carried out by using commercial codes of ANSYS CFX 120The study focuses on the effects of helix angle on flow and heat transfer characteristics,and heat exchanger performance is evaluated by entropy generation number based on the analysis of the second law of thermodynamicsThe results show that both the shell-side heat transfer coefficient and pressure drop decrease with the increase of the helix angle at certain mass flow rateThe latter decreases more quickly than the formerThe tangential velocity distribution on shell-side cross section is more uniform with continuous helical baffles than with segmental bafflesThe axial velocity at certain radial position decreases as the helix angle increases in the inner region near the central dummy tube,whereas it increases as the helix angle increases in the outer region near the shellThe heat exchange quantity distribution in tubes at different radial positions is more uniform at larger helix angleThe proportion of the entropy generation contributed by heat transfer in total entropy generation increases and the entropy generation number decreases with the increase of the helix angle at certain mass flow rate

Analyses on flow and heat transfer performance and entropy generation of heat exchanger with continuous helical baffles

Thermal resistance of heatsink was calculated with heat transfer empirical formulas and simulated with Icepak software,for testing accuracy of which,experiments of thermal resistances were carried out.Comparison of the results proved that Icepak simulation could meet engineering applying requirement,as well as modified empirical formulas method.

Thermal Design and Experimental Research on High-power IGBT Module Heatsink Applied in Rail Vehicle

Received: 18 April 2020 Accepted: 9 July 2020 In view of the heat transfer and ventilation characteristics of the Insulated Gate Bipolar Transistor (IGBT) in the Electric Multiple Unit (EMU), the authors aim to improve the traditional fin structure of the air-cooled heat exchanger (ACHE) and propose the use of corrugated fin structure. Using the computational fluid dynamics (CFD) technology, the ACHE with new fin structure was numerically simulated, and the temperature field, velocity field and pressure field at different fin corrugation angles and the synergy between the fields were analyzed. The results show that the improved fin structure can make the fluid flow in a corrugated flow channel, effectively increase the flow distance, and thus significantly enhance the turbulence performance of the fluid in the ACHE; the fin corrugation angle of 120 degrees is the key design point; compared with the traditional fin structure, the new fin structure improves the synergy between the various fields and increases the heat exchange efficiency. The research findings provide new ideas for the design of this type of ACHE.

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Numerical Simulation and Field Synergy Analysis of IGBT Air-Cooled Heat Exchanger for EMUs

Based on the heat transfer and flow resistance of diesel locomotive radiator, the influence was studied about the cooling air inlet speed on heat transfer coefficient and pressure loss of finned tube double channel radiator with louver by using CFD method. Temperature field, speed field and pressure field distribution of radiator calculation results were analyzed. The radiator was tested at different cooling air inlet speed, compared test results with simulation results, the greatest relative error of the heat transfer coefficient and pressure loss were 7.21% and 7.72%, respectively.

https://iopscience.iop.org/article/10.1088/1742-6596/1746/1/012048/pdf

Minghai Li

Papers

Numerical Simulation and Field Synergy Analysis of IGBT Air-Cooled Heat Exchanger for EMUs

Numerical Simulation Study on Air - side of Diesel Locomotive Finned Tube Double Channel Radiator