Aerodynamic sound generation in thermoviscous fluids: A canonical problem revisited

Although the Lighthill–Curle acoustic analogy theory is formally exact, presence of linear source terms related to viscous stresses and non-isentropic density changes makes it unsuitable for studying aerodynamic sound generation in low Reynolds number thermoviscous flows. Here we use an extension Ffowcs Williams Hawkings formulation, with effects explicitly included, find analytical solution canonical problem radiation from a circular cylinder immersed heat-conducting fluid rotating sinusoidally about its axis. Existing published solutions are compared earlier null result explained. The new analysis reveals dominant at Mach numbers be unsteady dissipation rather than Reynolds-stress quadrupoles, unless parameter B=αc2/cp zero.