Variable property piston effect

The use of the van der Waals equation of state for numerical simulation of the piston effect results in underpredicting the magnitude of the pressure wave by 38 % while overpredicting the acoustic heating by 13 % compared to using a real gas equation of state from the National Institute of Standards and Technology. When evaluating the piston effect at conditions typical of cryogenic storage systems, the pressure response of the fluid was observed to be tens of kilopascals. This pressure response was six orders of magnit ude larger than had been reported in previous research. The extent of the a coustic heating resulted in temperature increases in the bulk fluid that wa s measured in tens of milliKelvins. Previous researchers reported temperatu re increases in microKelvins, four orders of magnitude smaller than observe d in this research effort.