Based on observations data in the northeastern East China Sea and South China Sea,the applications of the vertical gradient method and the quasi-step function approximation method in shallow waters(depth <200 m),the shelf break waters(about 200 m)and open seas(depth>200 m)were analyzed to solve the horizontal discontinuity of the thermocline calculations in the shelf break waters.

Mathematical model of three dimensional steady heat transferring was established to evaluate the effects of air velocity on heat lamination height and vertical temperature distribution.

By using the method of Computational Fluid Dynamics(CFD), the office building is simulated which used the ceiling radiant cooling panels combined with the isolated outdoor air systems, and the indoor airflow velocity field, the temperature field and the vertical temperature gradient of the building are analyzed.

The temperature distribution in the occupied zone may be characterized by vertical temperature gradient(VTG) and the difference between temperature near the floor(at 0.

Based on the evaluation index of indoor air quality, this article analyzes the unique advantage of displacement ventilation on the improvement of IAQ ; discusses the effect of vertical temperature gradient and draft on thermal comfort and provides a combined system of displacement ventilation and cooled ceiling for reducing them.