A Development of the CFD based Icing Analysis System for Rotary Wing Aircraft
Abstract
This study aims to predict the torque variations and investigate the aerodynamic performances of rotary-wing aircraft (helicopters or tiltrotor aircraft) due to ice accumulations on the rotor blades in case the anti-/de-icing system is in failure mode. Ice accretions on critical surfaces can dramatically reduce aircraft performance, rendering safe flight impossible. In this emergency status, the pilot must recognize the abnormal signal of the flight to recover the vehicle safely. For rotary-wing aircraft, the detection oftorque variations may be a suitable way to make pilots aware of the situation. In this study, our group will develop a CFD-based icing analysis system to investigate the torque variation and its associated aerodynamic performance of the iced rotor blade. The system consists of three parts, airflow, droplet flow, and ice accretion, with nonlinear partial differential equations. The uniqueness of our approaches for iced rotor blades is classified into two parts, the numerical robustness of the droplet flow solver with a relaxation model, which has a time-dependent and locally constant artificial sound of speed in the additional term, and the semi-coupled solver for air-mixed droplet flow with the relaxation model in the rotating frame. The relaxation model shows strong robustness against negativity in a vacuum and preserves monotonicity without numerical oscillations. Also, the semi-coupled solver, including theCoriolis and centrifugal forces in the source terms of the governing equations, reflects the total relative energy and specific enthalpy for a rotating frame. Additionally, a multi-shot approach for computational efficiency is considered for ice accretions on thesections of the rotor blade. The sectional ice shapes will be interpolated to predict the torque variations and investigate the aerodynamic performance of a three-dimensional iced rotor blade. The hovering conditions of the rotor blade will be initially validatedusing the existing experimental data, and then the forward flight conditions will trace this process in the same manner. Lastly, the investigations of the torque variation and aerodynamic performance via this study can contribute to the guidelines in the pilot#s flight manuals for rotorcraft operating in the US Navy and the design of the anti-/de-icing system of rotor blades, which guaranteessafe flight from unrecognized icing issues.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Dec 15, 2023
- Source ID
- N629092412007
Entities
People
- Sungki Jung
Organizations
- Office of Naval Research
- United States Navy