Experimental and computational study of droplet shedding downstream of fins for application to compact heat exchangers.

摘要

This dissertation describes an experimental and computational study of droplet shedding from both a single plate fin and two plate fins in tandem. These fins are of the type used in fin matrices commonly used in compact condensers and evaporators. Liquid shedding from a fin is an important factor in determining the film thickness on the downstream fins in annular flow which greatly influences the heat transfer performance of the enhanced passages. The experimental system was a scaled-up version of a typical compact condenser or evaporator passage. The scaling was performed in such a way as to preserve the essential physics by insuring that important dimensionless numbers fell into the correct range. Two fin arrangements were investigated: a single plate fin and a double plate fin. For both configurations, the wake region consisted of two distinct regions: the near wake region, containing small and larger (3.5-4.5 mm) droplets, and the far wake region, containing a mist flow of only small droplets (50 to 1700