A Study of Thermal Radiation Transfer in a Solar Thruster

1991 ◽  
Vol 113 (4) ◽  
pp. 932-938
Author(s):  
S. Venkateswaran ◽  
S. T. Thynell ◽  
C. L. Merkle
Keyword(s):  
Heat Transfer ◽  
Solar Energy ◽  
Integral Method ◽  
Radiative Heat ◽  
Radiation Transfer ◽  
Operating Conditions ◽  
Two Dimensional ◽  
Radiation Problem ◽  
Parametric Studies ◽  
Overall Performance

Combined convective and radiative heat transfer in an axisymmetric solar thruster is analyzed. In a solar thruster, focused solar energy is converted into thermal energy by volumetric absorption, resulting in a significant increase in the temperature of the propellant gas. The heated gas is then expanded through a propulsive nozzle in order to generate thrust. In the present theoretical analysis, submicron size particles are employed for providing the mechanism of solar energy absorption. The two-dimensional radiation problem is solved using both an exact integral method and the P1-approximation. The overall energy transfer is solved iteratively by numerical means. The computational model is used to perform parametric studies of the effects of Boltzmann number, optical dimensions of the medium, and wall emissivity. The overall performance of the solar thruster is assessed by determining the thrust levels and the specific impulses of the device under different operating conditions.

Two-dimensional model of methane thermal decomposition reactors with radiative heat transfer and carbon particle growth

AIChE Journal ◽  
2011 ◽  
Vol 58 (8) ◽  
pp. 2545-2556 ◽  
Author(s):  
Cyril Caliot ◽  
Gilles Flamant ◽  
Giorgos Patrianakos ◽  
Margaritis Kostoglou ◽  
Athanasios G. Konstandopoulos
Keyword(s):  
Heat Transfer ◽  
Thermal Decomposition ◽  
Radiative Heat Transfer ◽  
Radiative Heat ◽  
Carbon Particle ◽  
Particle Growth ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Two Dimensional Model

Modeling of Turbulent Combustion and Radiative Heat Transfer in a Object-Oriented CFD Code for Gas Turbine Application

2008 ◽  
Author(s):  
Antonio Andreini ◽  
Matteo Cerutti ◽  
Bruno Facchini ◽  
Luca Mangani
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Radiative Heat Transfer ◽  
Turbulent Combustion ◽  
Radiative Heat ◽  
Object Oriented ◽  
Flame Stabilization ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Combustion Models

One of the driving requirements in gas turbine design is the combustion analysis. The reduction of exhaust pollutant emissions is in fact the main design constraint of modern gas turbine engines, requiring a detailed investigation of flame stabilization criteria and temperature distribution within combustion chamber. At the same time, the prediction of thermal loads on liner walls continues to represent a critical issue especially with diffusion flame combustors which are still widely used in aeroengines. To meet such requirement, design techniques have to take advantage also of the most recent CFD tools that have to supply advanced combustion models according to the specific application demand. Even if LES approach represents a very accurate approach for the analysis of reactive flows, RANS computation still represents a fundamental tool in industrial gas turbine development, thanks to its optimal tradeoff between accuracy and computational costs. This paper describes the development and the validation of both combustion and radiation models in a object-oriented RANS CFD code: several turbulent combustion models were considered, all based on a generalized presumed PDF flamelet approach, valid for premixed and non premixed flames. Concerning radiative heat transfer calculations, two directional models based on the P1-Approximation and the Finite Volume Method were treated. Accuracy and reliability of developed models have been proved by performing several computations on well known literature test-cases. Selected cases investigate several turbulent flame types and regimes allowing to prove code affordability in a wide range of possible gas turbine operating conditions.

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