Proposal of fluid dynamic models of vertical plume front vertical thermals

摘要

New fluid dynamic models for the front of the vertical plume and the vertical thermal are proposed. The model consists of the continuity equation, the mass conservative equation, and the Reynolds equation. The model is derived by integrations of basic equations for the front part. The entrainment coefficient and the drag coefficient are the basic parameters involved in the model. Several shape factors which are related to the front shapes are also included. The present model is compared with the experimental results of the fronts of the vertical plume and the vertical thermal, i.e., the travel speed, the width and the length of the front. The entrainment coefficient and the drag coefficient are deteremined in comparison with experimental results. The values of the entrainment coefficient for both flows are almost the same and do not depend on the flow types.