A novel numerical modeling approach to determine the temperature distribution in the cutting tool using conjugate heat transfer (CHT) analysis

2015 ◽  
Vol 80 (5-8) ◽  
pp. 1039-1047 ◽  
Author(s):  
Salman Pervaiz ◽  
Ibrahim Deiab ◽  
Essam Wahba ◽  
Amir Rashid ◽  
Cornel Mihai Nicolescu
Keyword(s):  
Heat Transfer ◽  
Numerical Modeling ◽  
Temperature Distribution ◽  
Conjugate Heat Transfer ◽  
Cutting Tool ◽  
Modeling Approach

A Study Regarding the Unsteady Heat Transfer and Phase Change

2014 ◽  
Vol 659 ◽  
pp. 353-358
Author(s):  
Gelu Coman ◽  
Cristian Iosifescu ◽  
Valeriu Damian
Keyword(s):  
Heat Transfer ◽  
Numerical Modeling ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Finite Elements ◽  
Experimental Research ◽  
Theoretical Study ◽  
Ice Formation ◽  
Unsteady Heat Transfer ◽  
Cooling Pipes

The paper presents the experimental and theoretical study for temperature distribution around the cooling pipes of an ice rink pad. The heat transfer in the skating rink track is nonstationary and phase changing. In case of skating rinks equipped with pipe registers, the temperature field during the ice formation process can’t be modeled by analytical methods. The experimental research was targeted on finding the temperatures in several points of the pad and also details on ice shape and quality around the pipes. The temperatures measured on the skating ring surface using thermocouples is impossible due to the larger diameter of the thermocouple bulb compared with the air-water surfaces thickness. For this reason we used to measure the temperature by thermography method, thus reducing the errors The experimental results were compared against the numerical modeling using finite elements.

scholarly journals Temperature Distribution and Numerical Modeling of Heat Transfer in Block 276 P1-Sand – Part I

2017 ◽  
Vol 3 (7) ◽  
pp. 30-40
Author(s):  
R. Trabelsi ◽  
A. C. Seibi ◽  
F. Boukadi ◽  
W. Chalgham ◽  
H. Trabelsi
Keyword(s):  
Heat Transfer ◽  
Numerical Modeling ◽  
Temperature Distribution

Numerical Study of Conjugate Heat Transfer Due to Growth of a Vapor Bubble During Flow Boiling of Water in a Microchannel

2007 ◽  
Author(s):  
A. Mukherjee
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Temperature Distribution ◽  
Cross Section ◽  
Vapor Bubble ◽  
Conjugate Heat Transfer ◽  
Flow Boiling ◽  
Wall Heat Flux ◽  
Channel Cross Section ◽  
Flux Boundary Condition

The present study is performed to numerically investigate temperature distribution at the channel walls during growth of a vapor bubble inside a microchannel. The microchannel is of 200 μm square cross section and a vapor bubble nucleates at one of the walls, with liquid flowing in through the channel inlet. Constant heat flux boundary condition is specified at the bottom wall of the microchannel. The complete Navier-Stokes equations along with continuity and energy equations are solved using the SIMPLER method. The liquid vapor interface is captured using the level set technique. The conjugate heat transfer problem is solved at the bottom and side walls. The bubble grows rapidly due to heat transfer from the walls and soon turns into a plug filling the entire channel cross section. The temperature distribution at the channel walls is studied for different values of wall heat flux. The bubble growth rate is found to increase with increase in wall heat flux. High temperatures are noted at the wall below the bubble base due to vapor contact causing axial temperature gradients. Areas of high heat transfer are also seen to exist in the thin layer of liquid between bubble and the channel sidewalls.

Large-Eddy Simulation and Conjugate Heat Transfer Around a Low-Mach Turbine Blade

2013 ◽  
Vol 136 (5) ◽  
Author(s):  
Florent Duchaine ◽  
Nicolas Maheu ◽  
Vincent Moureau ◽  
Guillaume Balarac ◽  
Stéphane Moreau
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Flow Field ◽  
Gas Turbines ◽  
Conjugate Heat Transfer ◽  
Separation Bubble ◽  
Suction Side ◽  
Free Stream Turbulence ◽  
Moderate Reynolds Number ◽  
Large Eddy

Determination of heat loads is a key issue in the design of gas turbines. In order to optimize the cooling, an exact knowledge of the heat flux and temperature distributions on the airfoils surface is necessary. Heat transfer is influenced by various factors, like pressure distribution, wakes, surface curvature, secondary flow effects, surface roughness, free stream turbulence, and separation. Each of these phenomenons is a challenge for numerical simulations. Among numerical methods, large eddy simulations (LES) offers new design paths to diminish development costs of turbines through important reductions of the number of experimental tests. In this study, LES is coupled with a thermal solver in order to investigate the flow field and heat transfer around a highly loaded low pressure water-cooled turbine vane at moderate Reynolds number (150,000). The meshing strategy (hybrid grid with layers of prisms at the wall and tetrahedra elsewhere) combined with a high fidelity LES solver gives accurate predictions of the wall heat transfer coefficient for isothermal computations. Mesh convergence underlines the known result that wall-resolved LES requires discretizations for which y+ is of the order of one. The analysis of the flow field gives a comprehensive view of the main flow features responsible for heat transfer, mainly the separation bubble on the suction side that triggers transition to a turbulent boundary layer and the massive separation region on the pressure side. Conjugate heat transfer computation gives access to the temperature distribution in the blade, which is in good agreement with experimental measurements. Finally, given the uncertainty on the coolant water temperature provided by experimentalists, uncertainty quantification allows apprehension of the effect of this parameter on the temperature distribution.

Investigation of Conjugate Heat Transfer in Brush Seals Using Porous Media Approach Under Local Thermal Non-Equilibrium Conditions

2015 ◽  
Author(s):  
Bo Qiu ◽  
Jun Li ◽  
Zhenping Feng
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Heat Generation ◽  
Frictional Force ◽  
Conjugate Heat Transfer ◽  
Frictional Heat ◽  
Equilibrium Conditions ◽  
Frictional Heat Generation ◽  
Brush Seal ◽  
Brush Seals

As a type of contacting seal technology, brush seals provide superior sealing performance and flexible behavior. Brush seals have found increasing application in more challenging high-temperature locations in recent years. Thus, the frictional heat generation between the seal bristles and mating surfaces is becoming another major concern for stable operation of brush seals. This study presents detailed investigations on the conjugate heat transfer behavior of brush seals using Computational Fluid Dynamics (CFD) and Finite Element Method (FEM) approaches. A dual-energy equation was proposed to describe the conjugate heat transfer in the porous bristle pack region under local thermal non-equilibrium conditions. The heat transfer CFD model was established with consideration of anisotropic thermal conductivity and a radius-dependent porosity of the bristle pack. The frictional heat generation was calculated from the product of the bristle-rotor frictional force and sliding velocity. The bristle-rotor frictional force was obtained from the brush seal FEM model with consideration of internal friction and aerodynamic load on the bristles. The temperature distribution of the brush seal was predicted at various operational conditions using the iterative CFD and FEM brush seal model. The effects of pressure ratios and rotational speeds on the temperature distribution and bristle maximum temperature of the brush seal were investigated based on the developed numerical approach. The effect of frictional heat generation on brush seal leakage was also analyzed.

Effects of Cooling Air on Performance of Turbine Blade Based on CHT Simulation

2012 ◽  
Vol 184-185 ◽  
pp. 184-187
Author(s):  
Jing Li ◽  
Zhen Xia Liu ◽  
Zhong Ren
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Surface Temperature ◽  
Turbine Blade ◽  
Conjugate Heat Transfer ◽  
Air Cooling ◽  
Work Efficiency ◽  
Surface Temperature Distribution ◽  
Heat Transfer Simulation ◽  
Cooling Air

A numerical model for conjugate heat transfer (CHT) simulation is established for a turbine blade with air cooling, and 3D heat transfer simulation is accomplished. Effects of different amount of cooling air on the surface temperature distribution, work, efficiency of turbine blade is studied. The results show that the surface temperature drops quickly with the increase of cooling air at beginning and then become mild, the blade work goes up, the efficiency goes down.

Conjugate Heat Transfer Simulation of a Radially Cooled Gas Turbine Vane

2004 ◽  
Author(s):  
Bruno Facchini ◽  
Andrea Magi ◽  
Alberto Scotti Del Greco
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Temperature Distribution ◽  
Gas Turbine ◽  
Conjugate Heat Transfer ◽  
Circular Cross Section ◽  
External Temperature ◽  
Turbine Vane ◽  
Heat Transfer Simulation ◽  
The Impact

A 3D conjugate heat transfer simulation of a radially cooled gas turbine vane has been performed using STAR-CD™ code and the metal temperature distribution of the blade has been obtained. The study focused on the linear NASA-C3X cascade, for which experimental data are available; the blade is internally cooled by air through ten radially oriented circular cross section channels. According to the chosen approach, boundary conditions for the conjugate analysis were specified only at the inlet and outlet planes and on the openings of the internal cooling channels: neither temperature distribution nor heat flux profile were assigned along the walls. Static pressure, external temperature and heat transfer coefficient distributions along the vane were compared with experimental data. In addition, in order to asses the impact of transition on heat transfer profile, just the external flow (supposed fully turbulent in the conjugate approach) was separately simulated with TRAF code too and the behaviour of the transitional boundary layer has been analyzed and discussed. Loading distributions were found to be in good agreement with experiments for both conjugate and non conjugate approaches, but, since both pressure and suction side exhibit a typical transitional behavior, HTC profiles obtained without taking into account transition severely overestimate experimental data especially near the leading edge. Results confirm the significant role of transition in predicting heat transfer and, therefore, vane temperature field when a conjugate analysis is performed.

Semi-analytical treatments of conjugate heat transfer

2012 ◽  
Vol 227 (3) ◽  
pp. 492-503 ◽  
Author(s):  
Mohammad Reza Hajmohammadi ◽  
Seyed Salman Nourazar ◽  
Ali Habibi Manesh
Keyword(s):  
Heat Transfer ◽  
Differential Equation ◽  
Temperature Distribution ◽  
Decomposition Method ◽  
Conjugate Heat Transfer ◽  
Adomian Decomposition Method ◽  
Differential Transform Method ◽  
Transform Method ◽  
Adomian Decomposition ◽  
Differential Transform

A new algorithm is proposed based on semi-analytical methods to solve the conjugate heat transfer problems. In this respect, a problem of conjugate forced-convective flow over a heat-conducting plate is modeled and the integro-differential equation occurring in the problem is solved by two lately-proposed approaches, Adomian decomposition method and differential transform method. The solution of the governing integro-differential equation for temperature distribution of the plate is handled more easily and accurately by implementing Adomian decomposition method/differential transform method rather than other traditional methods such as perturbation method. A numerical approach is also performed via finite volume method to examine the validity of the results for temperature distribution of the plate obtained by Adomian decomposition method/differential transform method. It is shown that the expressions for the temperature distribution in the plate obtained from the two methods, Adomian decomposition method and differential transform method, are the same and show closer agreement to the results calculated from numerical work in comparison with the expression obtained by perturbation method existed in the literature.

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