Innovative non-diffusive Vortex Method for Rotorcraft CFD Simulations
Naval Air Systems Command
This SBIR (Phase I) proposal will examine the feasibility of using the
Vorcat implementation of the grid-free vortex method to provide
accurate, real time simulations of rotor wake, specifically the tip
vortex structure, in various flight scenarios. Rotor wake flow is complex and poorly served by traditional Computational Fluid Dynamics (CFD) methodologies due to their inherent excessive numerical diffusion and this project capitalizes on the unique capabilities of the Vorcat code in efficiently capturing the physics of complex turbulent flows by using vortical elements to represent the vortices that lie at the heart of turbulent fluid motion.
The phase I study will be aimed at answering several questions that will establish the parameters controlling real time wake vortex dynamics and consequently in what way rotor downwash affects rotor aerodynamics and structural loading. In particular, this study will investigate several approaches for modeling rotor downwash and will establish the optimal setup that provides rapid and accurate results. This, in turn, will be utilized for a rigorous analysis which will determine the flow parameters that dominate wake vortex dynamics. If successful, the technology will be verified, validated and delivered to the Navy in later phases of this work.
The proposed study aims to exploit the opportunities presented by Vorcat to construct and implement reliable means for producing accurate rotor wake flow data so as to overcome the difficulties associated with current CFD solutions and to provide the Navy with an innovative methodology that can be turned into a encompass coupling between rotor wake flow and shipboard turbulence. Achieving the capabilities proposed here can be expected to significantly raise interest in Vorcat among companies and DOD agencies faced with complex applications including those with rotor flows and wakes thereby improving the overall marketability of the Vorcat approach. With the expertise acquired in this project, even more ambitious applications of Vorcat code can be anticipated in the future.
The successful solution of the rotor-rotor-wake flow field will allow us to expand the market niche of our technology so that Vorcat will become attractive to customers whose primary applications involve rotor/wake and general wake flows that play critical role in the analysis of flight safety. Rotor wake effects are important in other commercial applications as well, e.g., wind turbine placement in wind farms, hydro turbines operation under sea currents, among others.