TRANSIENT ANALYSIS OF COUPLED HEAT TRANSFER INSIDE CYLINDRICAL FOAM POROUS BLOCK WITH SUPERSONIC FLOW AROUND

Abstract In this paper, transient analysis on heat transfer across the residential building roof having various materials like wood wool, phase change material and weathering tile is performed by numerical simulation technique. 2-dimensional roof model is created, checked for grid independency and validated with the experimental results. Three different roof structures are included in this study namely roof with (i). Concrete and weathering tile, (ii). Concrete, phase change material and weathering tile and (iii). Concrete, phase change material, wood wool and weathering tile. Roof type 3 restricts 13% of heat entering the room in comparison with roof having only concrete and weathering tile. Also the effect of various roof layers’ thickness in the roof type 3 is investigated and identified that the wood wool plays the major role in arresting the entry of heat in to the room. The average reduction of heat is about 10 % for an increase of a unit thickness of wood wool layer.

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HEAT TRANSFER ENHANCEMENT IN A CHANNEL PARTIALLY FILLED WITH A POROUS BLOCK: LATTICE BOLTZMANN METHOD

International Journal of Modern Physics C ◽

10.1142/s0129183113500605 ◽

2013 ◽

Vol 24 (09) ◽

pp. 1350060 ◽

Cited By ~ 37

Author(s):

M. NAZARI ◽

M. H. KAYHANI ◽

R. MOHEBBI

Keyword(s):

Heat Transfer ◽

Nusselt Number ◽

Lattice Boltzmann Method ◽

Heat Transfer Enhancement ◽

Lattice Boltzmann ◽

Block Size ◽

Blockage Ratio ◽

Transfer Enhancement ◽

Porous Block ◽

Boltzmann Method

The main goal of the present study is to investigate the heat transfer enhancement in a channel partially filled with an anisotropic porous block (Porous Foam) using the lattice Boltzmann method (LBM). Combined pore level simulation of flow and heat transfer is performed for a 2D channel which is partially filled with square obstacles in both ordered and random arrangements by LBM which is not studied completely in the literature. The effect of the Reynolds number, different arrangements of obstacles, blockage ratio and porosity on the velocity and temperature profiles inside the porous region are studied. The local and averaged Nusselt numbers on the channel walls along with the respective confidence interval and comparison between results of regular and random arrangements are presented for the first time. For constant porosity and block size, the maximum value of averaged Nusselt number in the porous block is obtained in the case of random arrangement of obstacles. Also, by decreasing the porosity, the value of averaged Nusselt number is increased. Heat transfer to the working fluids increases significantly by increasing the blockage ratio. Several blockage ratios with different arrangements are checked to obtain a correlation for the Nusselt number.

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Base heat transfer in an axisymmetric supersonic flow

AIAA Journal ◽

10.2514/3.5813 ◽

1970 ◽

Vol 8 (5) ◽

pp. 974-976 ◽

Cited By ~ 3

Author(s):

LEROY S. FLETCHER

Keyword(s):

Heat Transfer ◽

Supersonic Flow ◽

Axisymmetric Supersonic Flow

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Computational study of unsteady gas flow in the combustion chamber of a ramjet engine with heat transfer

Вычислительные технологии ◽

10.25743/ict.2020.25.6.003 ◽

2021 ◽

pp. 50-61

Author(s):

Надежда Петровна Скибина

Keyword(s):

Heat Transfer ◽

Numerical Simulation ◽

Supersonic Flow ◽

Combustion Chamber ◽

Gas Flow ◽

Stokes Equations ◽

Heat Conducting ◽

Measuring Device ◽

Ramjet Engine ◽

Mach Numbers

Проведено численное исследование нестационарного турбулентного сверхзвукового течения в камере сгорания прямоточного воздушно-реактивного двигателя. Описана методика экспериментального измерения температуры на стенке осесимметричного канала в камере сгорания двигателя. Математическое моделирование обтекания исследуемой модели двигателя проводилось для скоростей набегающего потока M = 5 ... 7. Начальные и граничные условия задачи соответствовали реальному аэродинамическому эксперименту. Проанализированы результаты численного расчета. Рассмотрено изменение распределения температуры вдоль стенки канала с течением времени. Проведена оценка согласованности полученных экспериментальных данных с результатами математического моделирования. Purpose. The aim of this study is a numerical simulation of unsteady supersonic gas flow in a working path of ramjet engine under conditions identical to aerodynamic tests. Free stream velocity corresponding to Mach numbers M=5 ... 7 are considered. Methodology. Presented study addresses the methods of physical and numerical simulation. The probing device for thermometric that allows to recording the temperature values along the wall of internal duct was proposed. To describe the motion of a viscous heat-conducting gas the unsteady Reynolds averaged Navier - Stokes equations are considered. The flow turbulence is accounted by the modified SST model. The problem was solved in ANSYS Fluent using finite-volume method. The initial and boundary conditions for unsteady calculation are set according to conditions of real aerodynamic tests. The coupled heat transfer for supersonic flow and elements of ramjet engine model are realized by setting of thermophysical properties of materials. The reliability testing of numerical simulation has been made to compare the results of calculations and the data of thermometric experimental tests. Findings. Numerical simulation of aerodynamic tests for ramjet engine was carried out. The agreement between the results of numerical calculations and experimental measurements for the velocity in the channel under consideration was obtained; the error was shown to be 2%. The temperature values were obtained in the area of contact of the supersonic flow with the surface of the measuring device for the external incident flow velocities for Mach numbers M = 5 ... 7. The process of heating the material in the channel that simulated the section of the engine combustion chamber was analyzed. The temperature distribution was studied depending on the position of the material layer under consideration relative to the contact zone with the flow. Value. In the course of the work, the fields of flow around the model of a ramjet engine were obtained, including the region of supersonic flow in the inner part of axisymmetric channel. The analysis of the temperature fields showed that to improve the quality of the results, it is necessary to take into account the depth of the calorimetric sensor. The obtained results will be used to estimate the time of interaction of the supersonic flow with the fuel surface required to reach the combustion temperature.

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Numerical Study on 3D Coupled Heat Transfer of Thrust Chamber with Regenerative Cooling

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.52-54.1057 ◽

2011 ◽

Vol 52-54 ◽

pp. 1057-1061

Author(s):

Tao Nie ◽

Wei Qiang Liu

Keyword(s):

Heat Transfer ◽

Optimization Design ◽

Numerical Study ◽

Computing Time ◽

Three Dimensional ◽

Geometrical Model ◽

Performance Estimation ◽

Transfer Model ◽

Empirical Formulas ◽

Coupled Heat Transfer

To obtain temperature distribution in regenerative-cooled liquid propellant rocket nozzle quickly and accurately, three-dimensional numerical simulation employed using empirical formulas. A reduced one-dimensional model is employed for the coolant flow and heat transfer, while three dimensional heat transfer model is used to calculate the coupling heat transfer through the wall. The geometrical model is subscale hot-firing chamber. The numerical results agree well with experimental data, while temperature field in nozzle obtained. In terms of computing time and accuracy of results, this method can provide a reference for optimization design and performance estimation.

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Nusselt number evaluation for combined radiative and convective heat transfer in flow of gaseous products from combustion

Thermal Science ◽

10.2298/tsci110531083t ◽

2013 ◽

Vol 17 (4) ◽

pp. 1093-1106 ◽

Cited By ~ 1

Author(s):

Soraya Trabelsi ◽

Wissem Lakhal ◽

Ezeddine Sediki ◽

Mahmoud Moussa

Keyword(s):

Heat Transfer ◽

Radiation Effects ◽

Combustion Products ◽

Radiative Properties ◽

Inlet Temperature ◽

Gaseous Products ◽

Nusselt Numbers ◽

Coupled Heat Transfer ◽

Flow And Heat Transfer ◽

Fluid Properties

Combined convection and radiation in simultaneously developing laminar flow and heat transfer is numerically considered with a discrete-direction method. Coupled heat transfer in absorbing emitting but not scattering gases is presented in some cases of practical situations such as combustion of natural gas, propane and heavy fuel. Numerical calculations are performed to evaluate the thermal radiation effects on heat transfer through combustion products flowing inside circular ducts. The radiative properties of the flowing gases are modeled by using the absorption distribution function (ADF) model. The fluid is a mixture of carbon dioxide, water vapor, and nitrogen. The flow and energy balance equations are solved simultaneously with temperature dependent fluid properties. The bulk mean temperature variations and Nusselt numbers are shown for a uniform inlet temperature. Total, radiative and convective mean Nusselt numbers and their axial evolution for different gas mixtures produced by combustion with oxygen are explored.

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Coupled heat transfer in a composite material

Journal of Applied Mechanics and Technical Physics ◽

10.1007/bf00851570 ◽

1992 ◽

Vol 32 (4) ◽

pp. 600-607 ◽

Cited By ~ 4

Author(s):

A. M. Grishin ◽

A. N. Golovanov ◽

A. S. Yakimov

Keyword(s):

Heat Transfer ◽

Composite Material ◽

Coupled Heat Transfer

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