This article is concerned with a numerical study of mixed convection between two symmetrically heated corotating disks. Both thermal boundary conditions of constant wall temperature and uniform heat flux are considered. By applying the boundary-layer approximation and a linear relation for density variation in centrifugal force term, the governing equations reduce to a Boussinesq system of parabolic nature. The spatially developing flow and heat transfer are studied numerically. The effects of centrifugal buoyancy, Coriolis force, radial through-flow, and wall-heating on the flow structure and heat transfer performance are examined in detail. The results reveal that the centrifugal buoyancy, which was ignored in prior studies, is indeed a significant effect in this class of rotating flows. Nomenclature Cf = skin friction coefficient, fji(du/dz)w/(pu2 n/2) Grn = rotational Grashof number, (£l2s)pkTcs3lv2 h = heat transfer coefficient, W/(m2K) k = thermal conductivity, W/(mK) Nu = Nusselt number, hslk P = static pressure, N/m2 Pe = Peclect number, PrRe Pr = Prandtl number, via P', p' = dimensionless and dimensional pressure departure, respectively, P' = p'/pu2n q = heat flux, W/(m2s) R, r = dimensionless and dimensional radial coordinate, respectively, R = rls Re = through-flow Reynolds number based on inlet velocity, u-mslv Rev = tip Reynolds number, rl^llv = ReRoRl Re^ = rotational Reynolds number, £l2lv = ReRo Ro — rotation number, Hs/Min R' — dimensionless relative radial position, (r ~ rm}ls s = disk spacing, m