[[alternative]]Apply Unstructured Grid and Body-Fitting Coordinate Transformation to Simulate Fluid Flow

[[abstract]]本研究發展一數值模式以模擬各種不同幾何邊界下之二維不可壓縮層流流場。此數值模 式應用邊界附合座標轉換處理邊界,多區間型 展開方式及二邊界線性內插方式產生計算網格,並將網格予以非結構化,以採用非結構化網 格之資料結構記錄資料,使用雙倍密度網格及 Lagrangian Element之權重內插函數計算轉換參數,並與MAC計算方式結合成為一數值模式。本研究 以拉板淘穴、向後突張管路、垂直分歧管路及 均勻流通過圓形障礙物等四種流場為模擬對 象,將所得結果與前人研究比較、驗證。結果 顯示本數值模式具備精確性高、收斂速度快、使用彈性大、擴充能力強等優點,可用於解析 不同之二維不可壓縮層流流場。本研究結果顯 示以邊界附合座標轉換及非結構化網格之模式架構為有限差分法在流場模擬上開拓更廣之空間。[[abstract]]The goal of this research is intended to construct a numerical model to simulate two-dimensional incompressible laminar flows with different geometric boundaries. This numerical model applies Body- Fitting coordinate transformation, Multi-Block, Two-Boundaries linear interpolation to generate computational grid and the unstructured grid data format. Using double density grid and Lagrangian Element weighted function calculate transformation parameters and use MAC scheme as solver. Four various numerical two dimensional incompressible laminar flows have been simulated to approve simulation model which includes driven cavity, flow past a backward step, flow past a 90 degree bifurcation, and uniform flow past a circular cylinder. The numerical results show that the model has good accuracy, well convergent rate and robust. To sum up, this numerical model provides a new process for the finite difference method to cope with the geometric boundaries easily.[[sponsorship]]成功大學土木工程研究所; 中國土木水利工程學會; 教育部[[conferencetype]]國內[[conferencedate]]19931015~19931016[[booktype]]紙本[[iscallforpapers]]Y[[conferencelocation]]臺南市, 臺