Solutions for Unsteady Unidirectional Flow of a Generalized Burger Fluid in an Annular Pipe With Different Given Volume Flow Rate Conditions

環形管道中的廣義Burger流體之非穩定單向流動在給定不同體積流量條件下之解

林吟威(Yinwei Lin) ； 陳朝光(Cha'o-Kuang Chen)

《中國機械工程學刊》 41卷1期 (2020/02) Pp. 59-63

摘要

The velocity profile and pressure gradient of the unsteady state unidirectional flow of a generalized Burger fluid in an annular pipe with different given volume flow rate conditions are investigated in this study. Traditional models of this fluid is often solved by a partial (or ordinary) differential equation (PDE/ODE) with initial values or some boundary conditions. However, it is not enough to describe the phenomenon of Burger fluid in the real case. In this research, we added the inlet volume flow rate as an initial condition of the PDE. In order to understand the different flow characteristics, two basic flow situations are solved based on the prescribed flow conditions including a suddenly started flow and a constant accelerated flow, respectively. Finally, the linear acceleration and oscillatory flow is also considered in the last two cases.

關鍵字

velocity profile ； pressure gradient ； Burger fluid ； partial differential equation

並列摘要

本研究在給定不同體積流量之條件下，探討其在環形管道中之廣義Burger流體的非穩態單向流動的速度分佈和壓力梯度。這種流體的傳統模型通常透過具有初始值或一些邊界條件的偏（或常）微分方程（PDE/ODE）來求解。然而，在實際情況下，用描述Burger流體的現象是不夠的。在這個研究中，我們增加了入口體積流量作為PDE的初始條件。為了了解不同的流動特性，在給定流動條件之下，分別求解包括突然開始流動和恆定加速流動的兩個基本流動情況。最後，也考慮了線性加速度和振盪流動之流動條件在最後的兩種情況。