Shape optimization of non-linear swept ceiling fan blades through RANS simulations and Response Surface Methods

Ceiling fans are the most used resource for providing indoor thermal comfort in hot climates because of factors like low cost, easy availability and less electric consumption compared to air conditioning units. The fan industry of Pakistan is well-renowned on the national scale. In this paper, the features of the flow field generated by the ceiling fans under different geometric shapes are discussed. Specifically, the effect of forward elliptic sweep angle is studied on the performance of ceiling fans. Other geometric variables considered are tip width, root and tip angle of attack. The response variable considered for parametric analysis as well as optimization studies is the rated air delivery. The benchmark design is the reference blade being sold in market. By applying Design of Experiment (DOE), sixteen experiments are designed for new blades. These new blade designs are simulated through Reynolds-Averaged-Navier-Stokes (RANS) commercial flow solver. The computational model is developed around the same experimental facility and validated with experimental data. Subsequently, statistical tools are used to study the effect of individual parameters as well as their interactions. Finally, Response Surface Methodology (RSM) is used to find the optimal solution in the design space.