Validation of CFD codes for the helicopter wake in ground effect

Abstract

When a helicopter takes off, lands, or makes hovering or taxiing flights in ground effect, its downwash interferes with the ground. Encounters with such highly turbulent helicopter wakes have been blamed for two fixed-wing aircraft crashes in the United Kingdom. Additional incidents including tents blown away are reported in Japan. Due to these accidents, the Japan Aerospace Exploration Agency (JAXA) and the University of Glasgow (UoG) are investigating the helicopter wake structure in ground effect, especially during taxiing, by means of computational fluid dynamics (CFD). In this study, CFD codes of UoG and JAXA are validated through comparing numerical results of each party and flight experiment data. As a result, it is found that the CFD codes show qualitatively the same results each other and they are also close to the experiment.