Aerodynamic performance of transonic Bethe-Zel'dovich-Thompson flows past an airfoil

Dense gasdynamics studies the flow of gases in the thermodynamic region above the upper saturation curve, close to the liquid-vapor critical point. In recent years, great attention has been paid to certain substances, known as the Bethe-Zel'dovich-Thompson (BZT) fluids, which exhibit negative values of the fundamental derivative of gasdynamics for a whole range of temperatures and pressures in the vapor phase. This can lead to nonclassical gasdynamic behaviors, such as rarefaction shock waves, mixed shock/fan waves, and shock splitting. The uncommon properties of BZT fluids can find practical applications, for example, in the reduction of losses as a result of wave drag and shock/boundary-layer interaction in organic Rankine cycle turbines. The present work provides a detailed numerical study of transonic BZT fluid flows past a simplified configuration, represented by an isolated NACA0012 airfoil. The objective is to investigate the influence of BZT effects on the airfoil performance (specifically on the lift-to-drag ratio).