In this paper three-dimensional flows with conjugated heat transfer in multi-fluid and multi-channel compact heat exchangers are investigated. The underlying numerical solution method for the three-dimensional steady and unsteady incompressible Navier-Stokes and energy equations is presented, which combines efficient numerical techniques and parallel computing. The method is based on blockstructured grids with collocated arrangements of variables, a fully conservative finite volume discretization, an iterative pressure-correction method of SIMPLE type, a special parallelized ILU solver, a nonlinear multigrid method, and a grid partitioning technique.

SUMMARY The prediction of laminar flow in a bifurcating plane duct is presented. For a range of Reynolds numbers from 50 to 1500 and mass flow ratios in the junction from zero to the inflow massflux, the flow pattern and several global values, like pressure-drops, friction factors etc., are predicted. The aim of this investigation is to point out the relation between the energy losses and the parameters varied, which is possible by applying a parallel blockstructured multigrid code, with which, due to the high numerical efficiency of the algorithm and parallel computing, accurate results in short computing times are achievable, and therefore a high resolution of parameter fields are possible.

A finite volume multigrid procedure for the prediction of laminar natural convection flows is presented, enabling efficient and accurate calculations on very fine grids. The method is fully conservative and uses second-order central differencing for convection and diffusion fluxes. The calculations start on a coarse (typically 10 × 10 control volumes) grid and proceed to finer grids until the desired accuracy or maximum affordable storage is reached. The computing times increase thereby linearly with the number of control volumes. Solutions are presented for the flow in a closed cavity with side walls at different temperatures and insulated top and bottom walls. Rayleigh numbers of 104, 105 and 106 are considered. Grids as fine as 640 × 640 control volumes are used and the results are believed to be accurate to within 0–01%. Second-order monotonic convergence to grid-independent values is observed for all predicted quantities.

Identification and estimation of differential equation models for circadian data (1988) for visualizing data in four or more dimensions (1995) Penguin: A system for graphical data analysis (1992) Additive principle components: A method for estimating equations with small variance from data (1987) Principal curves and surfaces (1984) Interactive graphics for data analysis (1982) Wavelet methods for the inversion of certain homogeneous linear operators in the presence of noisy data (1994) S. Chen