The wide range of VTOL aircraft versatility and payload requirements has necessitated the development of a revolutionary VTOL vehicle design process. Based on the design goal, each component such as rotor and tail rotor, will be designed to meet the mission statement. When the initial assembly of the VTOL vehicle is drafted, aerodynamic analysis will be conducted to assess lift, drag, L/D, power, etc. of the aircraft. This is a single point aerodynamic analysis, which is common practice in VTOL vehicle. Then the obtained aerodynamic parameters will be balanced against other weight groups (engine, fuel, fuselage, gears, avionics, etc.) to determine eventual power requirement and payload. Several hundred CFD based steady-state aerodynamic analyses are often conducted. If each steady-state CFD takes a day to complete, the prototype design can take a year or more to complete. Subsequently, unsteady aerodynamic CFD analysis will be carried out to address power loading, disc loading, L/D, in ground and out of ground hover efficiency, etc. to identify payload, power requirement, and range. The unsteady CFD model is often large and consists of the entire aircraft, which can exceed 50M elements and often requires weeks or even months of traditional CPU based solver to complete one analysis. When hundreds of design iterations are common in a design cycle, the turnaround time becomes unrealistic. Recently, our ADS GPU flow solver has shown revolutionary type of speed-ups compared to using traditional CPUs. The GPU solver is validated for different types of application in turbomachinery and aerospace industries where speed-ups range from 20x to 50x. The revolutionary GPU technology has enabled ADS to take on complex unsteady aerodynamic analysis for VTOL vehicles, where the turn-around time can be reduced from weeks to less than a day. And with the added benefit to reduce steady-stage analysis to just a matter of minutes. The speed-ups allow ADS to perform many analyses to generate useful input data to create a CFD based VTOL vehicle design cycle efficiently to shorten design cycle and time to market to compete with many new emerging VTOL programs Thus the focus of the proposed effort is to adapt our GPU accelerated flow solver to the simulation requirements for future VTOL vehicle designs. Develop a multi-rotation axis model for the flow solver to enable steady state and transient analysis at speeds that can be integrated into the current design cycle.
