封闭圆内开缝圆自然对流的非线性特性研究

本文通过数值计算对封闭圆内开缝圆自然对流的非线性特性进行了研究。数值计算以整个流场为计算区域,采用非稳态数学模型和具有QUICK差分格式的SIMPLE算法。计算结果表明,在不同参数下流动和换热存在稳态定常解、周期性振荡解、拟周期性振荡解和非周期性振荡解。稳态定常解的相图是一个点;周期性振荡解的相图是一个极限环,对应功率谱含一个基频及其谐波;拟周期性振荡解的相图为环面,对应功率谱含两个不相关的频率及它们的线性组合频率;非周期性振荡解的功率谱为无规则的宽带连续谱。

Study of Nonlinear Characteristics of Natural Convection in Cylindrical Enclosure With Internal Slotted Cylinder

Non-linear characteristics of natural convection in cylindrical enclosure with internal slotted cylinder were investigated numerically.The numerical simulation took the complete flow field as calculation domain,adopting the unsteady mathematical model and SIMPLE algorithm with QUICK scheme.The numerical results showed that,the solutions could be steady,periodic oscillatory, quasi-periodic oscillatory,or non-periodic oscillatory with different parameters.The phase diagram of the steady solution is a point;the phase diagram of the periodic oscillatory solution is a limit cycle,and the corresponding power speetrum contains one basic frequency and harmonic frequencies: the phase diagram of the quasi-periodic oscillatory solution is a torus,and the corresponding power spectrum contains two independent frequencies and their linear combinations;the power spectrum of the non-periodic oscillatory solution is a broadband continuum.