Measurements of the turbulence modulation terms, i.e., u′giu′pl, between the gas and dispersed phase issued from a Simplex atomizer were carried out by a phase Doppler particle analyzer (PDPA) system. The Simplex atomizer is fueled by methanol with flow rate and pressure controlled at 1.39 g/s and 433 kPa, respectively. Results of the turbulence modulation for drop size less than 30 μm are presented. The turbulence modulation terms of Simplex spray is related to slip velocity, velocity fluctuations of both gas phase and dispersed phase, Reynolds stress of the gas phase and velocity correlation (u′pv′p) of the dispersed phase. The distributions of turbulence modulation terms in both axial and radial directions are similar. It is found that the turbulence modulation terms are higher in the spray sheet (i.e., R = 27-33 mm) for each size-class drops which increase from 0.8 m2/sec2 for 10 μm drops to 8.2 m2/sec2 for 30 μm drops, indicating the higher turbulence production of the gas phase due to the existence of larger drops. There are also turbulence modulations at radial position R = 10-20 mm which show the similar trend as Reynolds stress distribution at the same position. The Reynolds stress of gas phase and velocity correlation of dispersed phase are highly related to the turbulence modulation.
|Number of pages||11|
|Journal||International Journal of Fluid Mechanics Research|
|Publication status||Published - 1997|
All Science Journal Classification (ASJC) codes
- Mechanical Engineering
- Physics and Astronomy(all)