High Altitude Transitional Flow Computation for a Propulsion System Nacelle of MAAT Airship

The flow around the nacelles of high altitude airships is very important in order to assess the inlet conditions and losses associated to their propulsion systems. The aerodynamics prediction of low Re number flows is a problem usually associated to the lack of accuracy of most of the turbulence models in everyday use. Herein we present a laminar kinetic energy transitional model that is then applied on the analysis of the flow around an example of the MAAT airship nacelle. The model is also validated using several well known test cases from the literature. Results indicate the effects of accurate transition prediction in the redesign of the nacelle for improvement in efficiency.