Numerical Modeling and Experimental Testing of a Solar Grill

1993 ◽  
Vol 115 (1) ◽  
pp. 5-10 ◽  
Author(s):  
Ibrahim Olwi ◽  
Adel Khalifa
Keyword(s):  
Mathematical Model ◽  
Numerical Modeling ◽  
Fourth Order ◽  
Heat Balance ◽  
Experimental Testing ◽  
Balance Equations ◽  
Runge Kutta

A detailed study of a solar cooker used for meat grilling was performed. Experiments were undertaken to test the effects of several parameters on the cooker performance. A mathematical model for the solar grill was developed. Heat balance equations were solved using the fourth-order Runge-Kutta technique. It was concluded that an air-tight oven with double glazing and maximum meat charge will give the best performance and highest efficiency for the solar grill.

scholarly journals Modeling of atmospheric freeze-drying for sliced fruit

2018 ◽  
Author(s):  
Kyuya Nakagawa ◽  
Akane Horie ◽  
Takashi Kobayashi
Keyword(s):  
Mathematical Model ◽  
Glass Transition ◽  
Vapor Pressure ◽  
Heat Balance ◽  
Freeze Drying ◽  
Glassy State ◽  
Glassy Matrix ◽  
Reasonable Accuracy ◽  
Balance Equations ◽  
Apple Slices

A mathematical model that simulates atmospheric freeze-drying for apple slices was developed based on the classical mass and heat balance equations. When operated above the glass transition temperature, product shrinkage and micro-collapse due to the glass-rubber transition occurred. So, instead of assuming formation of dried and frozen zones, a glassy matrix with particular vapor pressure was assumed. Apparent vapor pressure of apple slices in the glassy state was experimentally measured and summarized in a diagram, and the values in this diagram were employed for the simulation. This approach well predicted drying kinetics with reasonable accuracy with simplified equations. Keywords: atmospheric freeze-drying; food; mathematical model; glassy state 

scholarly journals Some Numerical Methods and Comparisons for Solving Mathematical Model of Surface Decontamination by Disinfectant Solution

MATEMATIKA ◽  
2018 ◽  
Vol 34 (2) ◽  
pp. 271-291
Author(s):  
Chai Jin Sian ◽  
Yeak Su Hoe ◽  
Ali H. M. Murid
Keyword(s):  
Mathematical Model ◽  
Finite Difference ◽  
Finite Difference Method ◽  
Fourth Order ◽  
Difference Method ◽  
Kutta Method ◽  
Runge Kutta Method ◽  
Disinfectant Solution ◽  
Surface Decontamination ◽  
Runge Kutta

A mathematical model is considered to determine the effectiveness of disinfectant solution for surface decontamination. The decontamination process involved the diffusion of bacteria into disinfectant solution and the reaction of the disinfectant killing effect. The mathematical model is a reaction-diffusion type. Finite difference method and method of lines with fourth-order Runge-Kutta method are utilized to solve the model numerically. To obtain stable solutions, von Neumann stability analysis is employed to evaluate the stability of finite difference method. For stiff problem, Dormand-Prince method is applied as the estimated error of fourth-order Runge-Kutta method. MATLAB programming is selected for the computation of numerical solutions. From the results obtained, fourth-order Runge-Kutta method has a larger stability region and better accuracy of solutions compared to finite difference method when solving the disinfectant solution model. Moreover, a numerical simulation is carried out to investigate the effect of different thickness of disinfectant solution on bacteria reduction. Results show that thick disinfectant solution is able to reduce the dimensionless bacteria concentration more effectively

Research on On-Line Anti-Icing Technology for Carenary along Electrified Railway

2013 ◽  
Vol 676 ◽  
pp. 321-324
Author(s):  
Lei Guo ◽  
Qun Zhan Li
Keyword(s):  
Simulation Model ◽  
Heat Balance ◽  
Normal Operation ◽  
Balance Equations ◽  
Model Based ◽  
Static Var Generator ◽  
On Line ◽  
Electrified Railway ◽  
The Heat Balance

Accidents of icing on catenary have great impacts on normal operation of trains. An on-line anti-icing technology used static var generator (SVG) for catenary was proposed, which can prevent icing formation without interrupting trains normal operation. The heat balance equations for catenary were solved, whose results were compared with data provided by TB/T 3111 and testing show the equation was correct. The simulation model based on Matlab was bulit , whose results and analysis show the correctness of the method.

Calculation of Hourly Output of a Solar Still

1993 ◽  
Vol 115 (4) ◽  
pp. 231-236 ◽  
Author(s):  
V. B. Sharma ◽  
S. C. Mullick
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Heat Balance ◽  
Solar Still ◽  
Balance Equations ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Hourly Output ◽  
The Heat Balance

An approximate method for calculation of the hourly output of a solar still over a 24-hour cycle has been studied. The hourly performance of a solar still is predicted given the values of the insolation, ambient temperature, wind heat-transfer coefficient, water depth, and the heat-transfer coefficient through base and sides. The proposed method does not require graphical constructions and does not assume constant heat-transfer coefficients as in the previous methods. The possibility of using the values of the heat-transfer coefficients for the preceding time interval in the heat balance equations is examined. In fact, two variants of the basic method of calculation are examined. The hourly rate of evaporation is obtained. The results are compared to those obtained by numerical solution of the complete set of heat balance equations. The errors from the approximate method in prediction of the 24-hour output are within ±1.5 percent of the values from the numerical solution using the heat balance equations. The range of variables covered is 5 to 15 cms in water depth, 0 to 3 W/m2K in a heat-transfer coefficient through base and sides, and 5 to 40 W/m2K in a wind heat-transfer coefficient.

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