Side Of The Heating Cavity Gravity Wave Numerical Simulation Of The Evolution Process

Considering the previous studies on natural convection in a suddenly differentially heated cavity, the present thesis focuses on the development of the internal gravity waves in the cavity. Based on the previous experimental results, the governing equations and initial and boundary conditions are presented; The SIMPLE method is applied to investigate the natural convection flows; the development of the horizontal intrusion and cavity-scale oscillations are characterized in detail; and the mechanisms of the internal gravity are discussed.Numerical results in the present thesis demonstrate that separation, trailing waves and front circulation of the horizontal intrusion in a suddenly differentially heated cavity form, and front circulation may move to the opposite cold wall and dissipate. Due to the accumulation of the hot intrusion in the upward cold corner, a reverse flow and a clockwise circulation arise in the vicinity of the cold boundary layer if buoyancy overwhelms the inertial of the horizontal intrusion. The clockwise circulation may move back to the hot sidewall and ultimately result in cavity-scale oscillations. These cavity-scale oscillations are a typical internal gravity wave in the cavity, which further impact on the flows in the vertical thermal boundary layer and the stratification of the fluid in the core; that is, the oscillations may drive the trailing waves closer to the hot sidewall and in turn trigger instability of the vertical thermal boundary layer as well as change the structure and features of the vertical thermal boundary layer, and the hot horizontal intrusion may be split into two streams by the oscillations, thus stratifying the fluid in the core. In summary, the internal gravity waves are an important transient feature of natural convection in the suddenly differentially heated cavity.