Thermal Design Methodology for an Embedded Power Electronic Module Using Double-Sided Microchannel Cooling

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Manu Mital ◽  
Elaine P. Scott
Keyword(s):  
Heat Transfer ◽  
Design Methodology ◽  
Three Dimensional ◽  
Element Model ◽  
Thermal Design ◽  
Transfer Model ◽  
Power Electronic ◽  
Transfer Coefficients ◽  
Trade Offs ◽  
Parallel Channels

This paper presents a thermal design methodology for an integrated power electronic module (IPEM) using embedded, single-phase, and laminar-flow rectangular microchannels. Three-dimensional packaging of electronic components in a small and compact volume makes thermal management more challenging, but IPEMs also offer the opportunity to extract heat from both the top and the bottom side of the module, enabling double-sided cooling. Although double-sided cooling of IPEMs can be implemented using traditional aluminum heat sinks, microchannels offer much higher heat transfer coefficients and a compact cooling approach that is compatible with the shrinking footprint of electronic packages. The overall goal of this work was to find the optimal microchannel configuration for the IPEM using double-sided cooling by evaluating the effect of channel placement, channel dimensions, and coolant flow rate. It was found that the high thermal conductivity copper of the direct bonded copper (DBC) layer is the most feasible location for the channels. Based on a new analytical heat transfer model developed for microchannels in IPEM structures, several design configurations were proposed in this study that employ the microchannels in the copper layers of the top and bottom DBCs. The designs included multiple parallel channels in copper as well as a single wide microchannel. The analytical model was verified using a finite element model, and the competing design configurations were compared against a commercial cooler. For a typical IPEM structure dissipating on the order of 100W of heat, it was concluded that a single microchannel DBC heat sink is preferable to multiple parallel channels under a double-sided cooling configuration, considering thermal performance, pressure drop and fabrication trade-offs.

scholarly journals Fast three-dimensional heat transfer model for computing internal temperatures in the bearing housing of automotive turbochargers

2018 ◽  
Vol 21 (8) ◽  
pp. 1286-1297 ◽  
Author(s):  
Antonio Gil ◽  
Andrés Omar Tiseira ◽  
Luis Miguel García-Cuevas ◽  
Tatiana Rodríguez Usaquén ◽  
Guillaume Mijotte
Keyword(s):  
Heat Transfer ◽  
Coke Formation ◽  
Three Dimensional ◽  
Heat Transfer Model ◽  
Operating Conditions ◽  
Thermal Design ◽  
Working Fluid ◽  
Transfer Model ◽  
Lumped Model ◽  
Bearing System

Each of the elements that make up the turbocharger has been gradually improved. In order to ensure that the system does not experience any mechanical failures or loss of efficiency, it is important to study which engine-operating conditions could produce the highest failing rate. Common failing conditions in turbochargers are mostly achieved due to oil contamination and high temperatures in the bearing system. Thermal management becomes increasingly important for the required engine performance. Therefore, it has become necessary to have accurate temperature and heat transfer models. Most thermal design and analysis codes need data for validation; often the data available fall outside the range of conditions the engine experiences in reality leading to the need to interpolate and extrapolate disproportionately. This article presents a fast three-dimensional heat transfer model for computing internal temperatures in the central housing for non-water cooled turbochargers and its direct validation with experimental data at different engine-operating conditions of speed and load. The presented model allows a detailed study of the temperature rise of the central housing, lubrication channels, and maximum level of temperature at different points of the bearing system of an automotive turbocharger. It will let to evaluate thermal damage done to the system itself and influences on the working fluid temperatures, which leads to oil coke formation that can affect the performance of the engine. Thermal heat transfer properties obtained from this model can be used to feed and improve a radial lumped model of heat transfer that predicts only local internal temperatures. Model validation is illustrated, and finally, the main results are discussed.

Modeling of Steel Slab Reheating Process in a Walking Beam Reheating Furnace

2016 ◽  
Author(s):  
Guangwu Tang ◽  
Arturo Saavedra ◽  
Tyamo Okosun ◽  
Bin Wu ◽  
Chenn Q. Zhou ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Three Dimensional ◽  
Heat Transfer Model ◽  
Furnace Operation ◽  
Production Data ◽  
Heating Process ◽  
Transfer Model ◽  
Transfer Coefficients ◽  
Reheating Furnace ◽  
Reheating Process

Slab reheating is a very important step in steel product manufacturing. A small improvement in reheating efficiency can translate into big savings to steel mills in terms of fuel consumption and productivity. Computational fluid dynamics (CFD) has been employed in conducting numerical simulations of the slab reheating furnace operation. However, a full industrial scale three-dimensional (3D) simulation of a slab reheating furnace, while comprehensive, is not an efficient way to conduct broad studies of the slab heating process. In this paper, a comprehensive two-dimensional (2D) numerical heat transfer model for slab reheating in a walking beam furnace was developed using the finite difference method. The 2D heat transfer model utilizes the heat transfer coefficients derived from a 3D reheating furnace CFD model which was validated by using mill instrumented slab trials. The 2D heat transfer model is capable of predicting slab temperature evolutions during the reheating processes based on the real time furnace conditions and steel physical properties. The 2D model was validated by using mill instrumented slab trials and production data. Good agreement between the model predictions and production data was obtained.

Evaluation of Thermal Performance for Vacuum Glazing by Using Three-Dimensional Finite Element Model

2011 ◽  
Vol 492 ◽  
pp. 328-332 ◽  
Author(s):  
Zhi Ming Han ◽  
Yi Wang Bao ◽  
Wei Dong Wu ◽  
Zheng Quan Liu ◽  
Xiao Gen Liu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Performance ◽  
Simulation Analysis ◽  
Three Dimensional ◽  
Central Area ◽  
Element Model ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Vacuum Glazing ◽  
Three Dimensional Finite Element

Simulation analysis of thermal performance for vacuum glazing was conducted in this paper. The heat conduction through the support pillars and edge seal and the radiation between two glass sheets were considered. The heat conductance of residual gas in vacuum gap was ignored for a low pressure of less than 0.1Pa. Two pieces of vacuum glazing with sizes of 0.3 × 0.3 m and 1.0 × 1.0 m were simulated. In order to check the accuracy of simulations with specified mesh number, the thermal performance of a small central area (4mm×4mm) with a single pillar in the center was simulated using a graded mesh of 41×41×5 nodes. The heat transfer coefficients of this unit obtained from simulation and analytic prediction were 2.194Wm-2K-1and 2.257Wm-2K-1respectively, with a deviation of 2.79%. The three dimensional (3D) isotherms and two dimensional (2D) isotherms on the cold and hot surfaces of the specimens were also presented. For a validity of simulated results, a guarded hot box calorimeter was used to determine the experimental thermal performance of 1.0m×1.0m vacuum glazing. The overall heat transfer coefficients obtained from experiment and simulation were 2.55Wm-2K-1 and 2.47Wm-2K-1respectively, with a deviation of 3.14%.

Progress in the Modeling and Simulation of Flow Boiling Heat Transfer of Binary Fluids Using Advanced Multi-Fluid Modeling Techniques

2012 ◽  
Author(s):  
Vedanth Srinivasan ◽  
Rok Kopun
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Heat Flux ◽  
Phase Change ◽  
Bubble Dynamics ◽  
Flow Boiling ◽  
Three Dimensional ◽  
Transfer Model ◽  
Transfer Coefficients ◽  
Wide Range

In this paper, we discuss the implementation and testing of a novel boiling mass transfer model to simulate the thermal and phase transformation behavior, generated due to boiling of binary mixtures, using the commercial CFD code AVL FIRE® v2011. The phase change model, based on detailed bubble dynamics effects, is solved in conjunction with incompressible phasic momentum, turbulence and energy equations in a segregated fashion, to study the flow boiling process inside a rectangular duct. Full three dimensional validation studies including the effect of flow velocity and exit pressure conditions, acting on a wide range of operating wall (superheat) temperatures, clearly shows the suppression of heat and mass transfer coefficients with enhancement in flow convection. Competing mechanisms such as phase change process and turbulent convection are identified to influence the heat transfer characteristics. In particular, the varying influence of the mass transfer effects on the heat flux characteristics with alteration in wall temperature is well demonstrated. Comparisons of the predicted total heat flux, computed as the sum of the convection and phase change components, indicate a very good agreement with experimental data, wherever available. Description of the flow field inclusive of phasic fraction, temperature and velocity field provides extensive details of the multiphase behavior of the boiling flow. Some preliminary results on the phase change work flow to model heat transfer in cooling jackets, for automotive applications, is also discussed.

Analysis of 3D Stator Temperature Field in High Voltage and High Power PMSM

2012 ◽  
Vol 462 ◽  
pp. 775-782
Author(s):  
Feng Bo Qu ◽  
Wei Li Li ◽  
Ting Ting Chen ◽  
Zhi Peng Li
Keyword(s):  
Heat Transfer ◽  
Temperature Field ◽  
Permanent Magnet Synchronous Motor ◽  
Three Dimensional ◽  
Thermal Design ◽  
Temperature Fields ◽  
Axial Fan ◽  
Transfer Coefficients ◽  
Basic Hypothesis ◽  
Physical And Mathematical Models

Taking a 315kW, 6kV permanent magnet synchronous motor (PMSM) with solid rotor as an example, the physical and mathematical models of PMSM three dimensional temperature fields analysis are established according to the heat transfer principles. The basic hypothesis and boundary value problems of the solving region in the motor are also presented. The 3-D temperature field in stator of PMSM was calculated, and the influences of heat transfer coefficients with consideration of the axial wind or not on stator temperature were analyzed. By comparing the test results with the calculated results, the influences of axial wind on motor temperature were investigated. These conclusions provide a reference for thermal design of the motor with co-axial fan and enclosure cooling fan.

scholarly journals Heat Transfer in Rotating Serpentine Passages With Trips Normal to the Flow

1992 ◽  
Vol 114 (4) ◽  
pp. 847-857 ◽  
Author(s):  
J. H. Wagner ◽  
B. V. Johnson ◽  
R. A. Graziani ◽  
F. C. Yeh
Keyword(s):  
Heat Transfer ◽  
Turbine Blade ◽  
Large Scale ◽  
Flow Direction ◽  
Operating Conditions ◽  
Transfer Model ◽  
Transfer Coefficients ◽  
Flow Equations ◽  
Turbine Blade Cooling ◽  
Heat Transfer Coefficients

Experiments were conducted to determine the effects of buoyancy and Coriolis forces on heat transfer in turbine blade internal coolant passages. The experiments were conducted with a large-scale, multipass, heat transfer model with both radially inward and outward flow. Trip strips on the leading and trailing surfaces of the radial coolant passages were used to produce the rough walls. An analysis of the governing flow equations showed that four parameters influence the heat transfer in rotating passages: coolant-to-wall temperature ratio, Rossby number, Reynolds number, and radius-to-passage hydraulic diameter ratio. The first three of these four parameters were varied over ranges that are typical of advanced gas turbine engine operating conditions. Results were correlated and compared to previous results from stationary and rotating similar models with trip strips. The heat transfer coefficients on surfaces, where the heat transfer increased with rotation and buoyancy, varied by as much as a factor of four. Maximum values of the heat transfer coefficients with high rotation were only slightly above the highest levels obtained with the smooth wall model. The heat transfer coefficients on surfaces where the heat transfer decreased with rotation, varied by as much as a factor of three due to rotation and buoyancy. It was concluded that both Coriolis and buoyancy effects must be considered in turbine blade cooling designs with trip strips and that the effects of rotation were markedly different depending upon the flow direction.

scholarly journals Numerical simulation of variable thermal conductivity on 3D flow of nanofluid over a stretching sheet

2020 ◽  
Vol 9 (1) ◽  
pp. 233-243 ◽  
Author(s):  
Nainaru Tarakaramu ◽  
P.V. Satya Narayana ◽  
Bhumarapu Venkateswarlu
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Stretching Sheet ◽  
Three Dimensional ◽  
Variable Thermal Conductivity ◽  
Normal Velocity ◽  
Transfer Coefficients ◽  
Similarity Transformations ◽  
Frictional Coefficients ◽  
The Impact

AbstractThe present investigation deals with the steady three-dimensional flow and heat transfer of nanofluids due to stretching sheet in the presence of magnetic field and heat source. Three types of water based nanoparticles namely, copper (Cu), aluminium oxide (Al2O3), and titanium dioxide (TiO2) are considered in this study. The temperature dependent variable thermal conductivity and thermal radiation has been introduced in the energy equation. Using suitable similarity transformations the dimensional non-linear expressions are converted into dimensionless system and are then solved numerically by Runge-Kutta-Fehlberg scheme along with well-known shooting technique. The impact of various flow parameters on axial and transverse velocities, temperature, surface frictional coefficients and rate of heat transfer coefficients are visualized both in qualitative and quantitative manners in the vicinity of stretching sheet. The results reviled that the temperature and velocity of the fluid rise with increasing values of variable thermal conductivity parameter. Also, the temperature and normal velocity of the fluid in case of Cu-water nanoparticles is more than that of Al2O3- water nanofluid. On the other hand, the axial velocity of the fluid in case of Al2O3- water nanofluid is more than that of TiO2nanoparticles. In addition, the current outcomes are matched with the previously published consequences and initiate to be a good contract as a limiting sense.

Flow Past a Spinning Sphere With Surface Blowing and Heat Transfer

2005 ◽  
Vol 127 (1) ◽  
pp. 163-171 ◽  
Author(s):  
H. Niazmand ◽  
M. Renksizbulut
Keyword(s):  
Heat Transfer ◽  
Three Dimensional ◽  
Flow Regimes ◽  
Solid Sphere ◽  
Temporal Variations ◽  
Transfer Coefficients ◽  
Transfer Rates ◽  
Particle Spin ◽  
Flow Past ◽  
Angular Velocities

Computations are performed to determine the transient three-dimensional heat transfer rates and fluid forces acting on a stream-wise spinning sphere for Reynolds numbers in the range 10⩽Re⩽300 and angular velocities Ωx⩽2. In this Re range, classical flow past a solid sphere develops four different flow regimes, and the effects of particle spin are studied in each regime. Furthermore, the combined effects of particle spin and surface blowing are examined. Sphere spin increases drag in all flow regimes, while lift shows a nonmonotonic behavior. Heat transfer rates are not influenced by spin up to a certain Ωx but increase monotonically thereafter. An interesting feature associated with sphere spin is the development of a special wake regime such that the wake simply spins without temporal variations in its shape. For this flow condition, the magnitudes of the lift, drag, and heat transfer coefficients remain constant in time. Correlations are provided for drag and heat transfer.

Thermal Analysis of Cooling System in a Gas Turbine Transition Piece

2011 ◽  
Author(s):  
Jun Su Park ◽  
Namgeon Yun ◽  
Hokyu Moon ◽  
Kyung Min Kim ◽  
Sin-Ho Kang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Thermal Stresses ◽  
Cooling System ◽  
Structural Information ◽  
Thermal Analyses ◽  
Thermal Design ◽  
Transfer Coefficients ◽  
Transition Piece ◽  
Inlet Conditions

This paper presents thermal analyses of the cooling system of a transition piece, which is one of the primary hot components in a gas turbine engine. The thermal analyses include heat transfer distributions induced by heat and fluid flow, temperature, and thermal stresses. The purpose of this study is to provide basic thermal and structural information on transition piece, to facilitate their maintenance and repair. The study is carried out primarily by numerical methods, using the commercial software, Fluent and ANSYS. First, the combustion field in a combustion liner with nine fuel nozzles is analyzed to determine the inlet conditions of a transition piece. Using the results of this analysis, pressure distributions inside a transition piece are calculated. The outside of the transition piece in a dump diffuser system is also analyzed. Information on the pressure differences is then used to obtain data on cooling channel flow (one of the methods for cooling a transition piece). The cooling channels have exit holes that function as film-cooling holes. Thermal and flow analyses are carried out on the inside of a film-cooled transition piece. The results are used to investigate the adjacent temperatures and wall heat transfer coefficients inside the transition piece. Overall temperature and thermal stress distributions of the transition piece are obtained. These results will provide a direction to improve thermal design of transition piece.

Measurement and Modeling of Condensation Heat Transfer Coefficients in Circular Microchannels

2006 ◽  
Vol 128 (10) ◽  
pp. 1050-1059 ◽  
Author(s):  
Todd M. Bandhauer ◽  
Akhil Agarwal ◽  
Srinivas Garimella
Keyword(s):  
Heat Transfer ◽  
Flow Rate ◽  
Heat Transfer Model ◽  
Condensation Heat Transfer ◽  
Low Flow ◽  
Transfer Model ◽  
Shear Stresses ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Circular Microchannels

A model for predicting heat transfer during condensation of refrigerant R134a in horizontal microchannels is presented. The thermal amplification technique is used to measure condensation heat transfer coefficients accurately over small increments of refrigerant quality across the vapor-liquid dome (0<x<1). A combination of a high flow rate closed loop primary coolant and a low flow rate open loop secondary coolant ensures the accurate measurement of the small heat duties in these microchannels and the deduction of condensation heat transfer coefficients from measured UA values. Measurements were conducted for three circular microchannels (0.506<Dh<1.524mm) over the mass flux range 150<G<750kg∕m2s. Results from previous work by the authors on condensation flow mechanisms in microchannel geometries were used to interpret the results based on the applicable flow regimes. The heat transfer model is based on the approach originally developed by Traviss, D. P., Rohsenow, W. M., and Baron, A. B., 1973, “Forced-Convection Condensation Inside Tubes: A Heat Transfer Equation For Condenser Design,” ASHRAE Trans., 79(1), pp. 157–165 and Moser, K. W., Webb, R. L., and Na, B., 1998, “A New Equivalent Reynolds Number Model for Condensation in Smooth Tubes,” ASME, J. Heat Transfer, 120(2), pp. 410–417. The multiple-flow-regime model of Garimella, S., Agarwal, A., and Killion, J. D., 2005, “Condensation Pressure Drop in Circular Microchannels,” Heat Transfer Eng., 26(3), pp. 1–8 for predicting condensation pressure drops in microchannels is used to predict the pertinent interfacial shear stresses required in this heat transfer model. The resulting heat transfer model predicts 86% of the data within ±20%.

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