Rotorcraft & Aviation Technologies
CFDRC develops multi-physics software applications and delivers expert engineering design services for rotorcraft, including: cargo and utility helicopters, military scout and attack helicopters, advanced rotor technology, and integrated control systems analyses. We also provide systems design and analyses for a variety of aviation technologies and aircrew protection systems.
Rotor and Wake Effects
Accurate prediction of the unsteady aerodynamics and airloads characteristics of rotorcraft involves interaction and data transfer between several physical analysis modules, as well as numerical interface modules. CFDRC has developed:
- Near-field aerodynamic flowfield predictions with Navier-Stokes codes (e.g. OVERFLOW)
- Accurate and efficient Far-field flow predictions using Vorticity Transport methods
- A multidisciplinary environment that enables multi-level parallelism of coupled multi-physics simulations
Rotor Blade Vibration
The helicopter rotor operates in a highly dynamic and unsteady aerodynamic environment leading to severe aerodynamic loads on the rotor systems. These aeroelastic loads on the rotor blades result in large blade deformations which have a significant impact on the resulting flow field. CFDRC experience includes:
- High-fidelity multi-disciplinary analysis of the aerodynamic and aeroelastic interactions between the fuselage, rotor blades, vertical and horizontal tails
- Parallel scalability assessment of FEM codes with application in the RCAS framework for 3D solid elements
Helicopter Engine Inlet Flow Particle Separation
Inlet systems for some vehicles, such as helicopters, must be able to ingest significant quantities of sand, and separate these particles from the core air stream so that the engine can function properly. CFDRC has conducted detailed inlet system analysis to predict sand particle trajectory and separation characteristics. CFDRC has developed:
- Computational fluid dynamics (CFD) modeling and simulation of engine inlet flows
- Numerical prediction of small sand/dust particle ingestion
- Integrated IPS/Barrier filter system design capable of removing 95% of particles down to 10 microns
Rotorcraft Airframe Modeling & Simulation
Helicopter rotor flow-fields presents many challenges for analytical tools, including the flow field interaction between the rotor and airframe. CFDRC develops 3D models and performs multi-physics modeling and simulation to analyze this effect and improve designs. Some examples include:
- An interactive tool for healing of geometric models for meshing purposes, applied to Rotorcraft airframes
- Shrink-wrapping grid generation tools for automatic grid generation/li>
Brownout Flow Field Visualization
For a rotorcraft landing in conditions where there is an appreciable prevailing wind flow, the rotorwash induced wall jet interacts with the “upstream” approaching flow, causing a convergence line/zone. The dust lifted off of ground by the rotorwash meets this convergence, and is lifted into the air and is further mixed by the “ground vortex” created upstream. When this cloud of particulates passes between the pilot and the ground, visibility can be significantly reduced. CFDRC Experience includes:
- Fate Transport & Dispersion of fine particulates in a 3D modeling environment for urban and complex terrains
- Soil dispersion due to rocket plume impingement
- 3D visualization tools for dispersion applications
Aircrew Vibration Damping Systems
When a helicopter crashes, the occupants have an extremely short distance and time for the impact force to be dispersed. The physics involved during that short period determines the extent of the occupant injuries. CFDRC has developed and applied coupled physics-based and physiology-based modeling & simulation to analyze rotorcraft crash-worthiness and design shock absorbing systems to increase the survivability of aircrews. Out work in this field includes:
- Modeling Magneto-rheological (MR) helicopter aircrew seat suspensions coupled with the human body
- Analyzed new shock absorbing materials for aircrew vibration damping systems
