Time-averaged pressure drop induced by a jet pump in oscillatory flow

Area of Science:

• Thermodynamics
• Fluid Dynamics
• Acoustics

Background:

• Gedeon streaming significantly reduces the thermal efficiency of looped traveling-wave thermoacoustic engines.
• Jet pumps offer a potential solution to mitigate Gedeon streaming by generating a time-averaged pressure drop.

Purpose of the Study:

• Investigate the mechanism by which jet pumps suppress Gedeon streaming.
• Analyze the impact of dimensionless rounding, taper angle, and cross-sectional area ratio on jet pump performance.

Main Methods:

• Experimental setup to measure time-averaged pressure drop in oscillatory flow.
• Controlled experiments to characterize jet pump performance under varying geometric parameters.

Main Results:

• Time-averaged pressure drop and working efficiency increase with dimensionless rounding up to 0.15.
• Taper angles between 3° and 9° yield higher pressure drop and efficiency; angles beyond 9° degrade performance.
• Increasing the cross-sectional area ratio improves performance for taper angles between 3° and 9°.

Conclusions:

• Jet pump geometry critically influences Gedeon streaming suppression in thermoacoustic engines.
• Optimized dimensionless rounding, taper angle, and area ratio are key for enhancing engine efficiency.