Performance of Multiple Nozzle Eductor Systems with Several Geometric Configurations.

摘要

Cold flow tests of a four nozzle eductor system were conducted to evaluate the system's performance with the following geometric modifications: changing the area ratio of the mixing stack to primary flow nozzles from 3.0 to 2.5; adding a solid diffusor to the exit of the mixing stack; adding two- and three-ring diffusors to the exit of the mixing stack; adding film cooling ports along the length of the mixing stack; and combining the effects of film cooling ports, a two-ring diffusor and a shroud. Non-dimensional parameters governing the flow phenomena are developed from a one-dimensional analysis of a simple eductor system based on the conservation of momentum for an incompressible gas. The eductor performance is evaluated in terms of these non-dimensional parameters. Within the range of modifications considered, the configuration with the film cooling ports, shroud and two diffusor rings provided the best overall eductor system performance. (Author)