The role of thermodynamic effects in Cavitation: Impacts on cavitation structure and propagation of cavitation noise

Cavitation-induced vibration and noise in industrial systems have received increasing attention in recent years. In high-temperature fluid cavitation process, the influence of thermodynamic effects becomes a significant factor that cannot be neglected. Based on existing research on cavitation noise experiments conducted on orifice plates, the current study utilized large eddy simulations and the Ffowcs Williams-Hawkings formulation to simulate the cavitation characteristics and noise propagation of a single-hole orifice plate. The thermodynamic effects on the evolution of cavitation structure and the propagation of cavitation noise were analyzed. The increase in fluid temperature causes thermodynamic effects to begin to have a discernible impact and the maximum temperature difference reaches 4.208 K, influencing the growth rate of vapor volume. The vortex stretching term accounts for over 60 % of the relative energy, signifying its prominent role as the primary mechanism driving vorticity changes within the orifice. The thermodynamic effects also lead to shift in cavitation inception, with more small vortexes materializing in the cavitation zone. Cavitation noise manifests at high frequencies and exhibits monopole noise. Thermodynamic effects inhibit the cavitation noise induced by the baroclinic torque. As the relative variation rate of the baroclinic torque term rapidly decreases, the sound pressure level of cavitation noise is reduced. With the increase of fluid temperature, the sound pressure level at the orifice plate position decreased by 12 %, while downstream of the orifice plate the sound pressure level dropped by 8 %. The research presented herein significantly furthers the understanding of cavitation dynamics and the relationship between cavitation and noise. Moreover, it provides important guidance for predicting and controlling cavitation and noise propagation.