Numerical study of mixed convection in the annulus between eccentric rotating cylinders

Mixed convection of air with prandtl number of 0.7 in eccentric horizontalannuli with isothermal wall conditions was numerically investigated. the inner cylinderwas at a higher temperature and the inner and outer cylinders rotate either clockwiseor counter-clockwise at a constant angular velocity. the eects of parameters such asthe eccentricity of the axes, the rayleigh number and rotation direction were studied.the two-dimensional navier-stokes and energy equations were numerically solved in anorthogonal grid by employing a nite-volume method based on the simple algorithm.this orthogonality was achieved by employing a cylindrical bipolar coordinate system. useof this coordinate system has the privileges of orthogonal coordinate and simplicity ofcomputing dierent uxes involved. mean and local heat transfer results were obtained.the physics of the ow and the heat transfer is revealed by the streamlines and theisotherms obtained from the numerical solutions. flow and heat transfer are inuencedby the orientation and eccentricity of the inner cylinder. the present numerical results arein good agreement with the results of others for pure natural convection.