Mathematical modeling of natural convection in a vertical cylindrical tank with alternating-sign heat flux distribution on the wall

1996 ◽  
Vol 31 (2) ◽  
pp. 218-223 ◽  
Author(s):  
L. A. Moiseeva ◽  
S. G. Cherkasov
Keyword(s):  
Mathematical Modeling ◽  
Heat Flux ◽  
Natural Convection ◽  
Flux Distribution ◽  
Cylindrical Tank ◽  
Heat Flux Distribution

Natural Convection of Non-Newtonian Fluids About a Horizontal Surface in a Porous Medium

1987 ◽  
Vol 109 (3) ◽  
pp. 119-123 ◽  
Author(s):  
H. T. Chen ◽  
C. K. Chen
Keyword(s):  
Heat Flux ◽  
Porous Medium ◽  
Natural Convection ◽  
Power Law ◽  
Flux Distribution ◽  
Similarity Solutions ◽  
Iteration Scheme ◽  
Heat Flux Distribution ◽  
Runge Kutta Method ◽  
Power Law Index

The problem of natural convection of a non-Newtonian power-law fluid about a horizontal impermeable surface in the porous medium is considered, where the plate is assumed with a nonuniform heat flux distribution. The present study is based on the boundary layer approximation and only suitable for a high Rayleigh number. Similarity solutions are obtained by using the fourth-order Runge-Kutta method and the Nachtsheim-Swigert iteration scheme. The effects of the nonuniform wall heat flux qw(x) and the new power-law index n on the heat transfer characteristics are discussed.

Boundary Optimal Control of Natural Convection by Means of Mode Reduction

2000 ◽  
Vol 124 (1) ◽  
pp. 47-54 ◽  
Author(s):  
H. M. Park ◽  
W. J. Lee
Keyword(s):  
Optimal Control ◽  
Heat Flux ◽  
Natural Convection ◽  
Gradient Method ◽  
Flux Distribution ◽  
Boussinesq Equation ◽  
Heat Flux Distribution ◽  
Projected Gradient Method ◽  
Galerkin Procedure ◽  
Low Dimensional

We consider problems of controlling the intensity of the Rayleigh-Be´nard convection by adjusting the heat flux distribution at the boundary while keeping the heat input the same. The Karhunen-Loe`ve Galerkin procedure is used to reduce the Boussinesq equation to a low dimensional dynamic model, which in turn is employed in a projected gradient method to yield the optimal heat flux distribution. The performance of the Karhunen-Loe`ve Galerkin procedure is assessed in comparison with the traditional technique employing the Boussinesq equation, and is found to be very accurate as well as efficient.

scholarly journals Mathematical Modeling of Heat Flux Distribution in Raw Cotton Stored in Bunt

Engineering ◽  
2020 ◽  
Vol 12 (08) ◽  
pp. 591-599
Author(s):  
Karimov Abdusamat Ismonovich ◽  
Ismanov Muhammadziyo
Keyword(s):  
Mathematical Modeling ◽  
Heat Flux ◽  
Flux Distribution ◽  
Heat Flux Distribution

Heat Flux Distribution Over a Solar Central Receiver Using an Aiming Strategy Based on a Conventional Closed Control Loop

2017 ◽  
Author(s):  
Jesús García ◽  
Yen Chean Soo Too ◽  
Ricardo Vasquez Padilla ◽  
Rodrigo Barraza Vicencio ◽  
Andrew Beath ◽  
...  
Keyword(s):  
Heat Flux ◽  
Flux Distribution ◽  
Thermal Stresses ◽  
Control Strategies ◽  
Multiple Input Multiple Output ◽  
Control Loop ◽  
Heat Flux Distribution ◽  
Input Multiple Output ◽  
Solar Receiver ◽  
Solar Field

Solar thermal towers are a maturing technology that have the potential to supply a significant part of energy requirements of the future. One of the issues that needs careful attention is the heat flux distribution over the central receiver’s surface. It is imperative to maintain receiver’s thermal stresses below the material limits. Therefore, an adequate aiming strategy for each mirror is crucial. Due to the large number of mirrors present in a solar field, most aiming strategies work using a data base that establishes an aiming point for each mirror depending on the relative position of the sun and heat flux models. This paper proposes a multiple-input multiple-output (MIMO) closed control loop based on a methodology that allows using conventional control strategies such as those based on Proportional Integral Derivative (PID) controllers. Results indicate that even this basic control loop can successfully distribute heat flux on the solar receiver.

Studies on heat flux distribution on the membrane walls in a 600 MW supercritical arch-fired boiler

2016 ◽  
Vol 103 ◽  
pp. 264-273 ◽  
Author(s):  
Dalong Zhang ◽  
Chenwei Meng ◽  
Hai Zhang ◽  
Pengyuan Liu ◽  
Zhouhang Li ◽  
...  
Keyword(s):  
Heat Flux ◽  
Flux Distribution ◽  
Heat Flux Distribution
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