Two-Dimensional Diffuser Performance With Subsonic, Two-Phase, Air–Water Flow

Abstract

The pressure recovery performance of straight-wall, two-dimensional diffusers with air–water mixtures has been investigated, and their behavior as a function of gas volume flow ratio and diffuser geometry established within the limits of the experimental apparatus. The ranges of parameters investigated were: Gas volume flow ratio, β: 0 to 73 percent; area ratio, AR: 1.3 to 4; diffuser length to throat width ratio, N/W1 : 3, 6, and 18. Diffusers with air–water mixtures have the same general performance characteristics as diffusers with single-phase fluids, e.g., peak pressure recovery occurs near the onset of stall and decreases again for larger area ratios in the stalled flow regimes. In stalled flow regimes, appreciable pressure recovery may be achieved in a constant-area tailpipe downstream of the diffuser. The pressure recovery of diffusers with two-phase flow deteriorates with increasing air flow, especially after the two-phase flow regime changes from bubbly to churn-turbulent.