The Role of Modelling and Simulation in the Preparations for Flight Trials Aboard the Queen Elizabeth Class Aircraft Carriers

Abstract

This paper provides a brief overview of how modelling and simulation has been used to inform preparations for First of Class Flight Trials (FOCFT) aboard HMS Queen Elizabeth, the first of the United Kingdom’s two new Queen Elizabeth Class aircraft carriers, from the perspective of a collaborative research programme undertaken by industry and academia to develop high-fidelity simulations of the carrier’s ‘airwake’. Computer modelling of the unsteady air flow over the carrier, and of the aircraft flight dynamics, have been integrated into high-fidelity flight simulators at BAE Systems Warton, and at the University of Liverpool. The Queen Elizabeth Class (QEC) carriers have primarily been designed to operate the Short Take-Off and Vertical Landing (STOVL) variant of the Lockheed Martin F-35 Lightning II multirole fighter aircraft and will also operate a range of rotary-wing assets. Computational Fluid Dynamics (CFD) has been used to compute the time-varying air flow over and around the 280m long ship, along the F-35B landing approach path and up to 400m astern of the ship. The paper shows a selection of results from the full-scale CFD analysis, and the results from a small-scale experiment that was conducted to provide confidence in the validity of the computed airwakes. The QEC airwakes have been employed by BAE Systems in its fixed-wing flight simulator at Warton, where test pilots have conducted simulated deck landings for a variety of wind over deck conditions, so providing experience for F-35B test pilots and the ship’s Flying Control (FLYCO) crew ahead of FOCFT, which will be conducted later this year. Airwakes have also been implemented in the HELIFLIGHT-R flight simulator at the University of Liverpool, where helicopter landings to the QEC have been simulated using a generic medium-weight maritime-helicopter model. A selection of results from the helicopter flight simulator trials is presented in terms of the workload ratings reported by test pilots, and these are related to the characteristics of the computed airwake at the landing spots tested. The paper demonstrates how modelling and simulation can be used to reduce both the risk and cost of flight trials, by informing the FOCFT planning process, and by highlighting, in advance of the trials, which wind speed and azimuth combinations may require more focus.

Effect of modifications to island shape and geometrical configuration on the external aerodynamics of a generic aircraft carrier

“…24 The CFD simulations are able to capture the abrupt forward velocity deficit for the 3 ° -glideslope path between 1.4 and 2 ship lengths. 24,25…”

“…Aerodynamic studies have been carried out on the Queen Elizabeth class carrier by UK researchers [14][15][16] to provide airwake data to flight simulators for training of pilots as well as to map the airwake around the flight deck regions, especially with a viewpoint of optimizing the location of rotary aircraft landing points. 16 Other studies have focused on improving the flow in the bow region of the aircraft carrier by fitting passive devices such as CVGs, bow flaps, and cylindrical sections.…”

“…24 The CFD simulations are able to capture the abrupt forward velocity deficit for the 3 °-glideslope path between 1.4 and 2 ship lengths. 24,25 Methodology for quantifying pilot workload and burble effect A detailed methodology for quantifying the pilot workload and burble effect was developed in one of our earlier publications. 5 The aim of the exercise was to mathematically model the turbulence to indicate the increased pilot workload and burble effect in terms of the airflow parameters such as the velocities (u,w) and pressure (p) and its derived quantities such as TI and turbulence kinetic energy (TKE) based on studies undertaken by Rudowsky et al, 26 who showed that any decrease in forward velocity component (u) would be considered unfavorable for pilot workload and safety, as it directly reduces the lift force and causes a sinking effect and Vivaldi 27 who analyzed the effect of turbulence and crosswinds on the mental workload of pilots.…”

Towards the Determination of Safe Operating Envelopes for Autonomous UAS in Offshore Inspection Missions

“…In its most common form, the use of modelling and simulation for SHOL development has been the use of pilot-in-the-loop testing to derive helicopter/ship operational guidelines and to construct preliminary simulated SHOL envelopes [13,14]. Of particular note, piloted flight simulation was used extensively to prepare for the F-35B Lightning II FOCFTs on the UK's new aircraft carrier, HMS Queen Elizabeth [15].…”