With growing concerns about air pollution, Human Powered Vehicle (HPV) offers a possible solution. With limited power available from human muscle, HPVs must be as efficient as possible because aerodynamic drag is the dominant retarding force at high speed. Two fairings for the use cases of pure speed and everyday use are conceived, designed, implemented and operated where the key parameters of frontal area, surface area and shape are evaluated and compared with a benchmark model. The fairings are designed using the NACA 65-415, 66-018 and 66-021 airfoils. Computational fluid dynamics (CFD) simulations were done using the realizable k-ɛ model with scalable wall functions. In addition, low-speed comparative wind tunnel testing was conducted using the Taylor’s Wind Tunnel with 1/10 scale models. It was found that the pure speed fairing having the lowest values of frontal and surface area produced the lowest drag, followed by the benchmark model and lastly the everyday use model which has the highest values of the respective parameters. The same trends were found in the wind tunnel. Due to the CFD limitation of not simulating boundary layer transition, the shape parameter could not be evaluated and thus future simulations using the transition SST turbulence model is recommended.
|Number of pages||11|
|Journal||Iranian Journal of Science and Technology, Transactions of Mechanical Engineering|
|Publication status||Published - 24 May 2018|