Control of multiple-passage cannel flows using DBD plasma actuator

Abstract

Inside of fuel cells, heat exchanger, chemical reactors, and other industrial devices, the fluid flow comes into the inlet chamber and streams into many branch passages. A uniform flow distribution requirement is a common issue in those devices. In this study, the flow rate in branch channels and the pressure loss of multiple passage are investigated experimentally. As the first step, four kinds of multiple-passage channels are investigated from the view point of flow uniformity and pressure loss. Experiments are performed for the Reynolds number based on the bulk velocity and channel width at the main channel from 6.0×10² to 2.0×10³. The wall static pressure is measured, and the pressure loss and flow rate are evaluated. It becomes clear that the characteristic of a reverse flow passage has the highest performance for the flow rate distribution. In the second step, the dielectric barrier discharge plasma actuator (DBD-PA) is used for the reverse flow passage. The wave form with voltage of 5 kV and frequency of 2.5 kHz is applied to the electrode of actuator, and the position in which the actuator is installed is changed in four positions of the outside wall at inlet manifold. The velocity profiles are measured by a PIV system to clarify change of the velocity field with and without PA actuation. The results show that the pressure loss decreases and the flow rate in each branch passage improves by the effect of induced flow with PA. The effect becomes remarkable when PA is installed near the first branch channel. The flow uniformity and low pressure loss are related to the reduction of the recirculation region which exists at the inlet manifold.