Numerical Study of Chaotic Behavior under Conditions near the Critical Rayleigh-Bénard Convection in Rectangular Cavity

• Main Authors: Guo-Shuo Su, 蘇國碩
• Other Authors: 吳文忠
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/7vqc4e

碩士 === 國立虎尾科技大學 === 航空與電子科技研究所 === 103 === The objective of the present study is to explore flow field circum stances in a two-dimensional cavity for a range of Rayleigh number from 〖10〗^5 to 〖10〗^8, The study used the solution through Direct Numerical Simulation, and Navier-Stokes equations are sloved by using the fractional step method. The results exhibited with phase trajectory method and frequency spectrum. The results found that the hot wall as for the bottom, cold wall as above, in the aspect ratio of 1, the flow field at Ra=5×〖10〗^5, the overall flow field in a laminar flow state, when Ra increase to 6×〖10〗^6 change to periodic state until Ra=5×〖10〗^7 begin to Chaos. In an aspect ratio of 4, Ra=5×〖10〗^5, the flow field for the laminar flow state, the transition from laminar flow to a periodic state when Ra increased to 6×〖10〗^6, when Ra=〖10〗^7, he flow field in the period to maintain flow state until more than Ra=5×〖10〗^7, starting from various points in the flow field-flow generating chaotic period, all in under two conditions Ra=5×〖10〗^8 into turbulence. AR=4 spectral intensity and speed are higher than AR=1.