An Overview of Mountain Wave Concerns for Advanced Aeronautical Vehicle Development

As aircraft altitude performance increased to reach the jet stream and lower stratosphere pilots, passengers and design engineers became especially intrigued with turbulence and wave encounters. This proposed paper will cover aeronautical community experiences with wave and turbulent phenomena from the standpoint of structure and propulsion design issues. The intent is to briefly illustrate the impact of wave phenomena on high altitude gust loads, ride quality and system controls issues. Examples will be taken from NACA / NASA data obtained with gust recorders on the Project Jet Stream B-47, U-2 and supersonic aircraft. True gust velocity measurements from the B-57B and Blackbird airplanes will be illustrated as will high-altitude temperature transient data from the Concorde.

Early progress in forecasting high altitude turbulence and wave perturbations which showed convincing (empirical) relationships to mountain wave features will be reviewed. Recommendations for future field studies, numerical diagnoses and forecast development include sensing the vertical temperature and wind structure, partitioned analyses of the eddy energy, attention to fine-scale and production scale model upstream profile sensitivities and possible avenues to production forecast improvements.