粘性流体の熱音響理論 第1部

微小サイクルのエネルギー変換とエネルギー流束

抄録

Discussed are energy conversion and energy flux accompanied to oscillations of viscous fluid. The energy conversion per unit volume is shown to be ρ_m(∂T/∂p)_S«p⋅dS/dt»+«u⋅∇p» for a small cycle, for which variations of pressure p and entropy S are small. ρ_m is time average of the density, u is the velocity and ∇p is the pressure gradient. « » indicates double operations of spatial average over crosssectional area of flow-channel and time average. «u⋅∇p» is a negative quantity corresponding to dissipation due to viscosity of fluid. The average of energy flux is shown to be enthalpy flux ρ_m«H⋅u» approximately, in the case that the velocity u and the mass flux «ρ⋅u» are small and the wave length is long. ρ and H are variations of the density and the enthalpy respectively. The enthalpy flux for small cycle is shown to be summation of heat flux and work flux: ρ_m«H⋅u»=ρ_mT_m«S⋅u»+«p⋅u» where «p⋅u» is the work flux and ρ_mT_m«S⋅u» is the heat flux. Final discussions are on the energy conversion, the work flux and the heat flux of adiabatic reversible small-cycle, isothermal small-cycle, polytropic small-cycle, isobaric small-cycle and isochoric small-cycle.