The interaction of an asymmetrically heated Cube envelope exposed to turbulent external flow is numerically studied using a three dimensional computational fluid dynamics control volume approach with conjugate heat transfer, including thermal radiation effects. An analytical approach is used for thermal radiation modelling with an implicit boundary condition for convective and radiative heat transfer at solid-fluid interfaces. For external flow Reynolds numbers of 2 x 10(5)-10(6) and heat flux values of q = 20, 40 W m(-2), a weak but turbulent (Ra = 1.5-5 x 10(9)) buoyant flow is induced inside the cube. The temperature distribution of the inner surfaces is significantly affected by heat flux orientation with regard to external flow as well as the relative influence of convective and thermal radiation heat transfer. (C) 2008 Elsevier Ltd. All rights reserved.