DNS study on heat transfer of viscoelastic decaying isotropic turbulence

Direct numerical simulation (DNS) on viscoelastic decaying isotropic turbulence was carried out to investigate heat transfer reduction (HTR) mechanism. The transport equations of thermal fluctuation energy and heat flux were derived in both physical space and Fourier space. The effects of viscoelasticity on the transport equations were studied to analyze the mechanism of thermal fluctuation reduction and HTR. Statistics and Fourier space distributions of turbulent kinetic energy, thermal fluctuation energy, and turbulent heat flux of viscoelastic fluid were presented, and compared with those in Newtonian fluid. The effects of viscoelasticity on turbulent and thermal fluctuations were illustrated intuitively via curvelet method.