Aerodynamic Management by Mini-Propulsion System

• Main Authors: Wen-Ing Sheu, 許文英
• Other Authors: H.H. Chiu
• Format: Others
• Language: zh-TW
• Published: 1993
• Online Access: http://ndltd.ncl.edu.tw/handle/63022730914398187384

碩士 === 國立成功大學 === 航空太空工程學系 === 81 === One of the most important problems is how to control boun- dary- layer separation for aerodynamists. In this treatise, we try to give a new suggestion to this problem: introducing an artificial body force to the original boundary layer. This idea came from Prof. Chiu, and he named this under-developing con- trol system as the "Mini-Propulsion System".　　As a beginning, we want to build a mathematical base for this idea: using an idealized accelerating model with a known distribution function, then find the changes of flow by the computational simulation. First, solving an analytical flow field -- wedge geometric flow with similarity forcing, we found the possibly better types of forcing distribution function. Then, we tried to deal with the recirculation region behind the blunt body. We simulated the problem: a uniform flow over a sphere . Choosing three different positions under various pressure gra- dient conditions, and forcing the fluid particles near the boundary layer region with five kinds of forcing distribution function. We have had the results : under some special matches in the forcing function and position, we can have the shortened recirculation zone, the separation occurrence being delayed and great drag reduction as expect.