Study of turbulent flow characteristics in a 180°-bend annular diffuser with blowoff

An investigation of turbulent flows occurring in a 180 degrees-bend annular diffuser with an aperture in front of the bend is numerically and experimentally conducted. The blowoff mass flow rate and the inlet pressure have been systematically changed to study their influence on the diffuser performance. Results show that the pressure recovery coefficient increases with increasing blowoff mass flowrate and inlet pressure, but remains nearly constant if the inlet pressure is higher than about 10 bar. The numerical predictions are compared with the experimental data and excellent agreement is achieved. The results provide insight into the characteristics of flow in the diffuser and are useful for diffuser designs of engineering interest. (C) 1999 Elsevier Science Ltd.