Selection of Materials and Design of Multilayer Lightweight Passive Thermal Protection System

2015 ◽  
Vol 8 (2) ◽  
Author(s):  
Sachin Kumar ◽  
Shripad P. Mahulikar
Keyword(s):  
Finite Difference ◽  
Difference Scheme ◽  
Finite Difference Scheme ◽  
Thermal Protection ◽  
Thermal Protection System ◽  
Protection System ◽  
Explicit Finite Difference ◽  
Geometrical Dimensions ◽  
Combination Of Material ◽  
Selection Of

A methodology has been established aiming to design a lightweight thermal protection system (TPS), using advanced lightweight ablative materials developed at the NASA Ames Research Center. An explicit finite-difference scheme is presented for the analysis of one-dimensional transient heat transfer in a multilayer TPS. This problem is solved in two steps, in the first step, best candidate materials are selected for TPS. The selection of materials is based mainly on their thermal properties. In the second step, the geometrical dimensions are determined by using an explicit finite-difference scheme for different combinations of the selected materials, and these dimensions are optimized for the design of lightweight TPS. The best combination of material employs silicone impregnated reusable ceramic ablator (SIRCA), Saffil, and glass-wool for the first, second, and third layer, respectively.

scholarly journals A Multilevel Finite Difference Scheme for One-Dimensional Burgers Equation Derived from the Lattice Boltzmann Method

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Qiaojie Li ◽  
Zhoushun Zheng ◽  
Shuang Wang ◽  
Jiankang Liu
Keyword(s):  
Finite Difference ◽  
Difference Scheme ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Finite Difference Scheme ◽  
Numerical Solutions ◽  
Burgers Equation ◽  
One Dimensional ◽  
Explicit Finite Difference ◽  
Boltzmann Method

An explicit finite difference scheme for one-dimensional Burgers equation is derived from the lattice Boltzmann method. The system of the lattice Boltzmann equations for the distribution of the fictitious particles is rewritten as a three-level finite difference equation. The scheme is monotonic and satisfies maximum value principle; therefore, the stability is proved. Numerical solutions have been compared with the exact solutions reported in previous studies. TheL2, L∞and Root-Mean-Square (RMS) errors in the solutions show that the scheme is accurate and effective.

Dynamic Analysis of a Valve Spring With a Coulomb-Friction Damper

1990 ◽  
Vol 112 (4) ◽  
pp. 509-513 ◽  
Author(s):  
R. S. Paranjpe
Keyword(s):  
Finite Difference ◽  
Difference Scheme ◽  
Finite Difference Scheme ◽  
Coulomb Friction ◽  
Distributed Parameter ◽  
Friction Damper ◽  
Equivalent Viscous Damping ◽  
Valve Spring ◽  
Coulomb Damping ◽  
Explicit Finite Difference

The dynamic behavior of a distributed parameter valve spring with Coulomb damping has been modeled. Such a spring is described by a nonlinear, nonhomogeneous wave equation. This equation is solved using an explicit finite difference scheme. Some sample results are presented. The results of the finite difference scheme are compared with the results of an analytical solution for zero damping. The two compare very well. The spring is also modeled using an equivalent viscous damping coefficient. The results of this analysis are compared with those of the Coulomb damping analysis.

scholarly journals Explicit Finite-Difference Scheme for the Numerical Solution of the Model Equation of Nonlinear Hereditary Oscillator with Variable-Order Fractional Derivatives

2016 ◽  
Vol 26 (3) ◽  
pp. 429-435 ◽  
Author(s):  
Roman I. Parovik
Keyword(s):  
Finite Difference ◽  
Difference Scheme ◽  
Finite Difference Scheme ◽  
Fractional Derivatives ◽  
Stability And Convergence ◽  
Variable Order ◽  
The Difference ◽  
Explicit Finite Difference ◽  
The Stability ◽  
Variable Order Fractional Derivatives

Abstract The paper deals with the model of variable-order nonlinear hereditary oscillator based on a numerical finite-difference scheme. Numerical experiments have been carried out to evaluate the stability and convergence of the difference scheme. It is argued that the approximation, stability and convergence are of the first order, while the scheme is stable and converges to the exact solution.

Sign in / Sign up

Export Citation Format

Share Document