NUMERICAL SIMULATION OF THE FORMATION AND DEVELOPMENT OF INTERNAL GRAVITY WAVE IN A DIFFERENTIALLY HEATED CAVITY
侧加热腔体内重力波演化过程的数值模拟

A two dimensional numerical simulation of natural convection in a differentially heated cavity is performed.The evolution of the horizontal hot intrusion is observed and its physical properties are described. The numerical results show that,after the hot intrusion reaches the cold wall,some accumulates in the cold top corner,since the cold boundary layer flow cannot entrain all of the hot intrusion.Due to the hot fluid accumulation and the buoyancy effect,a reverse flow (opposing the cold boundary layer flow) first arises in the cold top corner,and then forms a clockwise local circulation.This circulation may move back to the hot wall, and ultimately a cavity-scale oscillation (i.e.internal gravity wave) is resulted between the hot and cold walls underneath the ceiling of the cavity.Such oscillation significantly decays with the passage of time,and almost disappears after two periods.