Method and system for modeling aerodynamic interactions in complex eVTOL configurations for realtime flight simulations and hardware testing
A method and system for modeling aerodynamic interactions in complex eVTOL configurations for realtime flight simulations and hardware testing which includes decomposing the aircraft into aerodynamic subcomponents, wherein the interactions between these components are handled by flow simulations of the surrounding fluid, which may be Euler flow CFD simulations. The system may be used as a flight simulator for pilot training in a realtime environment. The system may be used to support component testing using an interface to those components, such as flight electronics and actuators, to test the components in high fidelity simulations of actual flight demands on those components. The system may also be used to support design analysis in non-realtime to run numerous simulations on different designs and to provide comparative output.
1. A computer-implemented method of generating a fluid flow simulation over a computational volume, said method comprising:
obtaining a fluid-flow mesh or grid in computer memory, the fluid flow mesh or grid encompassing a computational volume defined in a first coordinate frame, the fluid flow mesh or grid comprising a plurality of cells or grid points;
obtaining an aircraft representation based in a second coordinate frame in computer memory;
obtaining initial conditions for the fluid flow mesh or grid in computer memory;
obtaining lifting surface elements of said aircraft representation in computer memory, said lifting surface elements representing slices of the lifting surfaces;
obtaining lift information from aerodynamic tables in computer memory for each slice;
fixedly coupling said second coordinate frame with said aircraft representation in said first coordinate frame with said computational volume, using a computer processor, wherein said aircraft representation comprises a representation of force actuators onto the fluid;
determining, using the computer processor, an updated induced velocity of the fluid based upon force inputs from the force actuators representing the aircraft frame using a discretized fluid flow solver;
determining, using the computer processor, the forces upon said slices of the lifting surfaces;
using the determined forces upon said slices of the lifting surfaces in said determination of said induced velocity;
determining, using the computer processor, a local Courant number for each mesh cell within the computational volume;
determining, using the computer processor, an updated total advection within the computational volume based upon the induced velocity and the aircraft motion, wherein said advection determination method is based upon the local Courant number for each mesh cell or grid point; and
storing an updated total advection in computer memory.
2. The method of claim 1 further comprising:
determining, using the computer processor, the fluid velocity at location of a rotor disc in the aircraft representation by sampling a plurality of points in the fluid-flow mesh at points associated with the rotor disc to create an idealized inflow velocity;
reconstructing the inflow velocity field through said rotor disc from the sampled point;
and applying the obtained forces and moments onto the fluid volume in a distributed manner.
3. The method of claim 2 further comprising:
obtaining, in computer memory, a ground reference frame coordinate system;
placing, using the computer processor, the aircraft frame into said ground reference frame coordinate system in an initial position;
determining, using the computer processor, changes in the aircraft position and attitude with regard to said ground reference frame coordinate system based upon forces on the aircraft using a multi rigid body simulator.
4. The method of claim 2 further comprising:
obtaining, in computer memory, a wind reference frame coordinate system;
placing, using the computer processor, the aircraft frame into said wind reference frame coordinate system in an initial position;
determining, using the computer processor, changes ii the aircraft position and attitude with regard to said wind reference frame coordinate system based upon forces on the aircraft using a multi rigid body simulator.
5. A flight simulator, said flight simulator comprising:
a flight simulation terminal adapted to receive commands from a test pilot, said flight simulation terminal coupled to a computer system, said flight simulation terminal comprising flight controls and a visual display; and
a computer system comprises a non-transitory computer storage medium comprising computer-executable instructions for generating a flight simulation for:
obtaining a fluid-flow mesh or grid in computer memory, the fluid flow mesh or grid encompassing a computational volume defined in a first coordinate frame, the fluid flow mesh or grid comprising a plurality of cells or grid points;
obtaining an aircraft representation based in a second coordinate frame in computer memory;
obtaining initial conditions for the fluid flow mesh or grid in computer memory;
obtaining lifting surface elements of said aircraft representation in computer memory, said lifting surface elements representing slices of the lifting surfaces;
obtaining lift information from aerodynamic tables in computer memory for each slice;
fixedly coupling said second coordinate frame with said aircraft representation in said first coordinate frame with said computational volume, using a computer processor, wherein said aircraft representation comprises a representation of force actuators onto the fluid;
determining, using the computer processor, an updated induced velocity of the fluid based upon force inputs from the force actuators representing the aircraft frame using a discretized fluid flow solver;
determining, using the computer processor, the forces upon said slices of the lifting surfaces;
using the determined forces upon said slices of the lifting surfaces in said determination of said induced velocity;
determining, using the computer processor, the local Courant number for each mesh cell within the computational volume;
determining, using the computer processor, an updated total advection within the computational volume based upon the induced velocity and the aircraft motion, wherein said advection determination method is based upon a local Courant number for each mesh cell or grid point; and
storing the updated total advection in computer memory;
obtaining, in computer memory, a ground reference frame coordinate system;
placing, using the computer processor, the aircraft frame into said ground reference frame coordinate system in an initial position;
determining, using the computer processor, changes in the aircraft position and attitude with regard to said ground reference frame coordinate system based upon forces on the aircraft using a multi rigid body simulator; and
creating, using the computer processor, a video output of the simulated flight for viewing on said visual display of said flight simulation terminal based upon the changes in aircraft position and attitude.
6. A component test system, said system adapted to test aircraft components during flight simulations using load experienced during the simulation, said system comprising:
an aircraft component, said aircraft component electronically coupled to a bench test computer system; and
a computer system comprises a non-transitory computer storage medium comprising computer-executable instructions for generating a bench test environment for:
obtaining a fluid-flow mesh or grid in computer memory, the fluid flow mesh or grid encompassing a computational volume defined in a first coordinate frame, the fluid flow mesh or grid comprising a plurality of cells or grid points;
obtaining an aircraft representation based in a second coordinate frame in computer memory;
obtaining initial conditions for the fluid flow mesh or grid in computer memory;
obtaining lifting surface elements of said aircraft representation in computer memory, said lifting surface elements representing slices of the lifting surfaces;
obtaining lift information from aerodynamic tables in computer memory for each slice;
fixedly coupling said second coordinate frame with said aircraft representation in said first coordinate frame with said computational volume, using a computer processor, wherein said aircraft representation comprises a representation of force actuators onto the fluid;
determining, using the computer processor, an updated induced velocity of the fluid based upon force inputs from the force actuators representing the aircraft frame using a discretized fluid flow solver;
determining, using the computer processor, the forces upon said slices of the lifting surfaces;
using the determined forces upon said slices of the lifting surfaces in said determination of said induced velocity;
determining, using the computer processor, a local Courant number for each mesh cell within the computational volume;
determining, using the computer processor, an updated total advection within the computational volume based upon the induced velocity and the aircraft motion, wherein said advection determination method is based upon the local Courant number for each mesh cell or grid point; and
storing the updated total advection in computer memory;
obtaining, in computer memory, a ground reference frame coordinate system;
determining, using the computer processor, the inputs to be directed to said aircraft component; and
sending, using the computer processor, the inputs to said aircraft component.
7. The component test system of claim 6 further comprising:
a load application device, said load application device adapted to provide external loads to said aircraft component,
and wherein said computer storage medium comprising computer-executable instructions for:
determining, using the computer processor, the loads upon said aircraft component; and
sending, using the computer processor, instructions to said load application device to load said aircraft component with said loads.