Flight simulators are integral to the design/development, testing/qualification, training and research communities and their utilisation is ever expanding. The use of flight simulation to provide a safe environment for pilot training, and in research and development, must be underpinned by quantification of simulator fidelity. While regulatory simulator standards exist for flight training simulators and new standards are in development, previous research has shown that current standards do not provide a fully quantitative approach for assessing simulation fidelity, especially in a research environment. This paper reports on progress made in a research project at the University of Liverpool (Lifting Standards), in which new predicted and perceptual measures of simulator fidelity have been developed. The new metrics have been derived from handling qualities engineering practice. Results from flight tests on the National Research Council (Canada) Bell 412 ASRA research aircraft and piloted simulation trials using the HELIFLIGHT-R simulator at Liverpool are presented to show the efficacy of adopting a handling qualities approach for fidelity assessment. Analysis of the new metrics has shown an appropriate degree of sensitivity to differences between flight and simulation.

Boundary-layer noise produced by rough surfaces is a potential contributor to airframe noise. In this paper, an attempt is made to assess the surface roughness noise for a conceptual Silent Aircraft design SAX-40 using a prediction model described in previous theoretical work (Liu and Dowling(12)). Estimates of three idealised test cases show that surface roughness could produce a relatively high noise level and enhance the trailing-edge noise somewhat. Roughness height and roughness density are two significant parameters which affect surface roughness noise, with roughness height having the more dominant effect. The distribution of roughness noise sources decreases in the streamwise direction on the SAX-40 surface. Two candidate rough surfaces are selected for SAX-40 to keep surface roughness noise at a negligible level and to meet an aggressive noise target.

This paper assesses the feasibility of the Adaptive Torsion Wing (ATW) concept to replace conventional ailerons and enhance the manoeuvrability of a MALE UAV. The ATW concept is a thin-walled closed section two-spar wingbox whose torsional stiffness can be adjusted through the chord-wise position of the front and rear spar webs. The reduction in torsional stiffness allows external aerodynamic loads to induce aeroelastic twist that can be used as a function of the flight conditions to obtain a desired roll control authority. Modelling of the concept was performed using a conceptual design tool developed in MATLABTM. The variation of structural figures of merit are evaluated and discussed. Finally, an MDO study was performed to have in-depth assessments of the potential benefits of the ATW in replacing ailerons and providing sufficient roll control.

This work considers the effects of camber morphing, both in magnitude and chord position, on the performance of a generic unmanned air vehicle (UAV). The focus is to maximise appropriate aerodynamic factors across the mission by optimising the wing camber. Specifically, the enhancement of range, endurance, and stall speed is sought by means of maximising their aerodynamic performance parameters, CL/CD, CL3/2/CD, and CLmax respectively. An analysis of the effects of camber morphing is carried out using the vortex panel code, XFOIL, utilising aerofoils from the NACA four-digit family. The results are then adjusted to account for 3D flow factors such as induced drag, offering a more realistic appraisal of their effectiveness. Flight testing is then performed on four wings of fixed aerofoil sections, optimised for each performance characteristic, to validate the trends observed in the XFOIL data onboard a 1·64m span aircraft.

A procedure for defining an empirical formula for the mass estimation of the fore and aft wings field Uof a medium range box wing aircraft is described. The procedure is based upon the work of Howe for estimating the wing mass of conventional cantilever wing aircraft. The paper outlines the procedure used to relate conventional cantilever wings to box wing aircraft wings. Using a vortex lattice tool, finite element methods and regression analysis, the modification performed on the coefficient in Howe’s method to enable its use on a medium range box wing aircraft is outlined. The results show that the fore and aft wings would use the same correction coefficient and that the aft wing would therefore be lighter than the fore wing on a medium range box wing aircraft.