Multi-objective aerodynamic shape optimization of small livestock trailers

This paper presents a formal optimization study of the design of small livestock trailers, within which the majority of animals are transported to market in the United Kingdom. The benefits of employing a headboard fairing to reduce aerodynamic drag without compromising the ventilation of the animals’ micro-climate are investigated using a multi-stage process involving Computational Fluid Dynamics (CFD), Optimal Latin Hypercube (OLH), Design of Experiments (DoE) and Moving Least Squares (MLS) metamodels. Fairings are parameterised in terms of three design variables and CFD solutions are obtained at 50 permutations of design variables. Both global and local search methods are employed to locate the global minimum from metamodels of the objective functions and a Pareto front is generated. The importance of carefully selecting an objective function is demonstrated and optimal fairing designs, offering drag reductions in excess of 5% without compromising animal ventilation, are presented.