Experimental and simulation studies on the performance of standing wave thermoacoustic prime mover for pulse tube refrigerator

• A twin standing-wave TAPM is studied with He, Ar, N2 and their binary mixtures.
• Experimental resonance frequency, f is predicted fairly well by DeltaEc simulation.
• DeltaEc gives larger pressure amplitude, ΔP & lower temp. difference across stack ΔT.
• High mass number working fluid gives lower f and larger ΔP but has higher ΔT values.
• Optimal gas mixture must be used for lower f and larger ΔP but with lower ΔT values.

The thermoacoustic prime mover (TAPM) has gained considerable attention as a pressure wave generator to drive pulse tube refrigerator (PTR) due to no moving parts, reasonable efficiency, use of environmental friendly working fluids etc. To drive PTCs, lower frequencies (f) with larger pressure amplitudes (ΔP) are essential, which are affected by geometric and operating parameters of TAPM as well as working fluids. For driving PTRs, a twin standing wave TAPM is built and studied by using different working fluids such as helium, argon, nitrogen and their binary mixtures. Simulation results of DeltaEc are compared with experimental data wherever possible. DeltaEc predicts slightly increased resonance frequencies, but gives larger ΔP and lower temperature difference ΔT across stack. High mass number working fluid leads to lower frequency with larger ΔP, but higher ΔT. Studies indicate that the binary gas mixture of right composition with lower ΔT can be arrived at to drive TAPM of given geometry.