LINEAR-STABILITY OF CHANNEL FLOW WITH HEAT-TRANSFER - THE IMPORTANT ROLE OF REFERENCE TEMPERATURE

Poiseuille flow in a two-dimensional channel with the special boundary condition of constant wall temperature on both sides is used to demon strate the important role of reference temperature T-R. The local bulk temperature is shown to be the natural choice. Only with this referen ce temperature the physics of flow stability is clearly revealed, Gene ral results are gained by an asymptotic expansion method which is demo nstrated to be equivalent to a so-called combined method. This method combines asymptotic considerations and highly accurate numerical solut ions of the nonexpanded basic equations. (C) 1997 Elsevier Science Ltd .