Scramjet analysis with chemical reaction using three-dimensional approximate factorization

1989 ◽  
Author(s):  
J. WAI ◽  
D. SOMMERFIELD
Keyword(s):  
Chemical Reaction ◽  
Three Dimensional ◽  
Approximate Factorization

scholarly journals Implicit Euler Method for Three-Dimensional Turbomachinery Flow Calculation

1993 ◽  
Author(s):  
Shih H. Chen ◽  
Anthony H. Eastland
Keyword(s):  
Three Dimensional ◽  
Prediction Method ◽  
Minimum Cost ◽  
Inviscid Flow ◽  
Turnaround Time ◽  
Euler Method ◽  
Second Order ◽  
Approximate Factorization ◽  
Implicit Euler Method ◽  
Numerical Instabilities

A compressible three-dimensional implicit Euler solution method for turbomachinery flows has been developed. The goal of the present study is to develop an efficient and reliable method that can be used to replace the semi-empirical, semi-analytical quasi-three-dimensional turbomachinery flow prediction method currently being used for multi-stage turbomachinery design at early design stages. Currently, a methodology has been developed based on an inviscid flow model (Euler solver) and tested on single blade rows for validation. The method presented here is derived from the Beam and Warming implicit approximate factorization (AF) finite difference algorithm. To avoid high frequency numerical instabilities associated with the use of central differencing schemes to obtain a spatial second order accuracy, a combined explicit and implicit artificial dissipation model is adopted. This model consists of a second order implicit dissipation and mixed second/fourth order explicit dissipation terms. A Cartesian coordinate H-grid generated by a three-dimensional interactive grid generator developed by Beach is used. Results for SSME High Pressure Fuel Turbine are presented and the comparison with experimental data is discussed. The use of the present implicit Euler method and the three-dimensional turbomachinery interactive grid generator shows that turnaround time could be as short as one day using a workstation. This allows the designers to explore optimal design configurations at minimum cost.

Micro-Patterning of Silicon by Frictional Interaction and Chemical Reaction

1998 ◽  
Vol 120 (2) ◽  
pp. 353-357 ◽  
Author(s):  
Dae-Eun Kim ◽  
Jae-Joon Yi
Keyword(s):  
Chemical Reaction ◽  
Low Cost ◽  
Three Dimensional ◽  
Single Crystal Silicon ◽  
Crystal Silicon ◽  
Micro Electro Mechanical Systems ◽  
Micro Patterning ◽  
Frictional Interaction ◽  
Micro Structures ◽  
Micro Patterns

In this paper a novel and economical method of generating three-dimensional micro-patterns on single crystal silicon without the need for a mask is presented. The technique is based on the fundamental understanding of frictional interaction at light loads. Micro-patterning is done through a two-step process that comprises mechanical scribing and chemical etching. The basic idea is to induce micro-plastic deformation along a prescribed track through frictional interaction between the tool and the workpiece. Then, by exposing the surface to a chemical under controlled conditions, preferential chemical reaction is induced along the track to form hillocks about 5 μm wide and 1 μm high. This method of micro-machining may be used for making patterns in micro-electro-mechanical systems (MEMS) at low cost. Furthermore, this process demonstrates how microtribological processes can be utilized in the fabrication of micro-structures.

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