TAYLOR-COUETTE FLOW WITH BUOYANCY - ONSET OF SPIRAL FLOW

Numerical simulations of the effects of buoyancy on the stability and morphology of Taylor-Couette flow have been conducted. The three-dimen sional equations of motion are discretized using a hybrid Chebyshev co llocation/Fourier spectral method. The problem geometry consists of an air-filled vertical annulus with radius ratio, eta=r(i)/r(o)=0.5 (whe re r(i) and r(o) are the inner and outer radii, respectively), and asp ect ratio, Gamma=L/(r(o)-r(i))=10 (where L is the height of the annulu s). The Bow is generated by combined heating and rotation of the inner cylinder. Results for various values of the Reynolds number, Re, and Grashof number, Gr, show several bifurcations of the system. The most notable change in flow structure with increasing rotational effects is the onset of spiral flow in certain parameter ranges. Compared to exi sting analytical and experimental results, the current numerical resul ts show good agreement. (C) 1997 American Institute of Physics.