Towards Shape Optimization of Radiator Cooling Tanks

With increased demand for improvements in the efficiency and operation of all automotive engine components, including those in the engine cooling system, there is a need to develop a set of virtual tools that can aid in both the evaluation and design of automotive components. In the case of automotive radiators, improvements are needed in the overall pressure drop as well as the coolant flow homogeneity across all radiator tubes. The latter criterion is particularly important in the reduction of premature fouling and failure of heat exchangers. Rather than relying on ad hoc geometry changes with the goal of improving the performance of radiators, the coupling of CFD flow simulations with numerical shape optimization methods could assist in the design and testing of automotive heating and cooling components. The first phase of this study focuses on the development and evaluation of optimization criteria for pressure drop and mass flow rate distribution in a water-to-air automotive heat exchanger. CFD simulations based on simplified two-dimensional, 5- or 10-tube, models of a radiator, are used to investigate the effect of inlet, outlet, and tank geometry changes on pressure drop and mass flowrate distribution, and to quantify these effects in terms of two proposed performance measures. The results, which showed improvements in both pressure drop and flow uniformity for a simplified two-dimensional geometry, justify the optimization criteria that were developed, as well as the potential of shape optimization methods combined with CFD to improve heat exchanger designs.