scholarly journals Toward an equation of state for finite-difference computer program

1974 ◽  
Author(s):  
R.C. Schroeder ◽  
W.H. McMaster
Keyword(s):  
Equation Of State ◽  
Finite Difference ◽  
Computer Program

The Response of Defects Containing Water under Dynamic Loads

2011 ◽  
Vol 225-226 ◽  
pp. 933-936 ◽  
Author(s):  
Zhe Ming Zhu
Keyword(s):  
Equation Of State ◽  
Finite Difference ◽  
Finite Difference Method ◽  
Strain Rate ◽  
Difference Method ◽  
Failure Criterion ◽  
Explosive Charge ◽  
Dynamic Loads ◽  
Test Results ◽  
Simulation Results

A crater blasting model of rock with pre-existing defects under blasting loads is established by using finite difference method. The defects are saturated with water and are randomly distributed. The defects include voids, pores and small open joints. A shock equation of state (EOS), obtained from the existing test results, is employed for the granite near the explosive charge, and for the granite far from the charge, a linear EOS is applied. A modified principal stress failure criterion is applied to determining the granite statuses. The granite dynamic strengths, which increase with strain rate, are calculated from the existing test results. The simulation results show that under blasting, the strength of wet rock is lower than that of dry rock.

scholarly journals Analysis of Thermal and Insulation Performance of Double Glazed Window Doped With Paraffin Wax

2020 ◽  
Vol 38 (3A) ◽  
pp. 383-393
Author(s):  
Jalal M. Jalil ◽  
Salih M. Salih
Keyword(s):  
Heat Capacity ◽  
Thermal Properties ◽  
Finite Difference ◽  
Computer Program ◽  
Time Lag ◽  
Ambient Condition ◽  
Paraffin Wax ◽  
Summer Climate ◽  
Temperature Time ◽  
Insulation Performance

In this paper, a numerical investigation has been performed to study the effect of varying the thermal properties of the paraffin wax on the performance of a double glazed window doped with it during the summer climate of Baghdad (33.3 °N, 44.4 °E). Using FORTRAN (f 90) constructed computer program, finite difference combined with the enthalpy method was utilized to deal with the conduction with phase change problems within the wax. Results obtained show that increasing the density, latent heat, and thickness of the paraffin wax PCM) would increase the temperature-time lag and reduce the temperature decrement factor of the double glazed window, and as a result, improve comparatively the performance of the unit. In contrast, changing the specific heat capacity of the paraffin wax is not a productive (inefficient) technique to develop the performance of the unit. Besides, the recommended thickness of the window (thickness of the PCM) under the ambient condition of Baghdad should be 20 mm or higher.

Effects of Landfill Cover Design on Methane Recovery Systems

1983 ◽  
Vol 105 (4) ◽  
pp. 528-535
Author(s):  
J. W. Massmann ◽  
C. A. Moore
Keyword(s):  
Finite Difference ◽  
Computer Program ◽  
Methane Yield ◽  
Methane Recovery ◽  
Landfill Cover ◽  
Recovery System ◽  
Clay Cover ◽  
Cover Design ◽  
Oxygen Poisoning ◽  
Reliable Methods

A finite difference computer program to aid in optimizing landfill cover design was developed by the authors. The program was used to compare the methane yield from sand-covered and clay-covered landfills equipped with methane recovery systems. The results of this comparison and a brief description of the finite difference program are presented in this paper. These results indicate that a clay cover can restrict air inflow into the landfill system, thus preventing oxygen poisoning of the methane-producing organisms. The practice of monitoring methane to air ratios in the pipelines of the recovery system in order to forewarn of oxygen infiltration into the fill material was shown to be ineffective in some situations. More reliable methods to forewarn of oxygen poisoning were suggested.

Closed-End Cylindrical Shell Under Line Load Along a Generator

1980 ◽  
Vol 102 (1) ◽  
pp. 90-97 ◽  
Author(s):  
U. S. Chawla
Keyword(s):  
Cylindrical Shell ◽  
Finite Difference ◽  
Discrete Element Method ◽  
Computer Program ◽  
Circular Cylindrical Shell ◽  
Numerical Technique ◽  
Elastic Analysis ◽  
Line Load ◽  
Shell Plate ◽  
Free Body

This paper presents a numerical technique for elastic analysis of a thin circular cylindrical shell with end plates under uniform line load along a generator. This technique is based upon the discrete element method. An accurate set of the governing differential equations due to Vlasov is used. The derivatives with respect to the circumferential coordinate are replaced by finite difference relationships. The end plate is analyzed as a free body under unit concentrated edge loads and the resulting coefficients are used to satisfy continuity conditions at the shell-plate junction. A computer program to implement this technique is developed and results are compared with those published in the literature. A number of new results are presented.

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