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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。
In this paper, we study the nonlinear characteristics of the natural convection of the slit circle in a closed circle by numerical calculation. Numerical calculation Taking the entire flow field as the calculation area, unsteady mathematical model and SIMPLE algorithm with QUICK difference format are adopted. The results show that steady-state steady solutions, periodic oscillation solutions, quasi-periodic oscillation solutions and non-periodic oscillation solutions of flow and heat transfer exist under different parameters. The phase diagram of the stationary steady solution is a point. The phase diagram of the periodic oscillation solution is a limit cycle, and the corresponding power spectrum contains a fundamental frequency and its harmonics. The phase diagram of the quasi-periodic oscillation solution is toroidal and corresponds to the power spectrum There are two uncorrelated frequencies and their linear combination of frequencies; the power spectrum of the aperiodic oscillation solution is an irregular wideband continuum.