Simulation study of helicopter ship landing procedures incoporating measured flow data

The aim of this article is to investigate the use of inverse simulation to help identify those regions of a ship's flight deck which provide the safest locations for landing a rotorcraft in various atmospheric conditions. This requires appropriate information on the wind loading conditions around a ship deck and superstructure, and for the current work, these data were obtained from wind tunnel tests of a ship model representative of a typical helicopter carrier/assault ship. A series of wind tunnel tests were carried out on the model in the University of Glasgow's 2.65 × 2.04 m wind tunnel and three-axis measurements of wind speed were made at various locations on the ship deck. Measurements were made at four locations on the flight deck at three different heights. The choice of these locations was made on the basis of preliminary flow visualization tests which highlighted the areas where the most severe wind effects were most likely to occur. In addition, for the case where the wind was from 30 to starboard, measurements were made at three further locations to assess the extent of the wake of the superstructure. The generated wind profiles can then be imposed on the inverse simulation, allowing study of the vehicle and pilot response during a typical landing manoeuvre in these conditions. The power of the inverse simulation for this application is demonstrated by a series of simulations performed using configurational data representing two aircraft types, a Westland Lynx and a transport helicopter flying an approach and landing manoeuvre with the worst atmospheric conditions applied. It is shown from the results that attempting to land in the area aft of the superstructure in a 30° crosswind might lead to problems for the transport configuration due to upgusts in this area. Attempting to perform the landing manoeuvre in an aggressive manner is also shown to lead to diminished control margin in higher winds

A Direct Viscid-Inviscid Interaction Scheme for the Prediction of 2-Dimensional Aerofoil Performance in Incompressible Flow. G.U. Aero Report 8701

Summary: This paper presents a method for assessing two-dimensional aerofoil performance characteristics including trailing edge and gross laminar separation. The model used is a direct viscid-inviscid interaction scheme based on a vortex panel method with boundary layer corrections and an inviscidly modelled wake. The Integral boundary layer methods adopted behave well in the region of separation and thus, good comparisons with measured separation characteristics are obtained. Generally the predictions of lift and pitching moment may be considered to be within the experimental error, but where this is not the case, the applicability of the modelling technique is discussed

An Examination of the Dynamic Stalling of Two Wing Planforms. G.U. Aero Report 9526

No abstract available

Development of a European Aircraft Design Consortium in Higher Education. TEMPUS Joint European Project 11 79-90/1. Interim report for year 1990-1991. Departmental report no. 9222

Summary: Most of the effort to date has gone into establishing the executive structure which will direct and monitor the educational and technical programmes and the program of staff/student assignments between Czechoslovakia and the participating EEC Institutions. The activities are described in 8 main sections

A Feasibility Study into the Generation of Transverse and Longitudinal Vortices in Low Speed Wind Tunnels. Internal Report 9828

Summary: This report details the work carried out during a fundamental study into the generation of transverse and longitudinal vortices in the working sections of wind tunnels. In the initial phases of the project, effort was focused on the generation and measurement of longitudinal vortex pairs to mimic the vortex system produced by the Westland Helicopter's Vane tip. The results from this part of study have already been used in an EPSRC funded study of main rotor blade-vortex interaction (BVI). Attention was then directed towards the development and testing of a transverse vortex generator for studies of tail rotor BVI. The successful demonstration of this generator has resulted in a follow-on EPSRC funded study of helicopter tail rotor BVI in a larger wind tunnel facility

An Investigation of Three-Dimensional Dynamic Stall. G.U. Aero Report 9542

The following report summarises a three year research programme in the Department of Aerospace Engineering, University of Glasgow to collect unsteady pressure data on the dynamic stalling characteristics of finite wing planforms. The original motivation for the work lay in the pressing need for a greater understanding of the strongly three-dimensional effects in the tip region of helicopter rotors. In this study, a new data collection system capable of sampling 200 parallel channels at up to 50kHz per channel has been developed. Additionally, a new support structure, actuation mechanism and hydraulic supply system was established for the test programme. Together, these new systems were used to conduct tests on two wing planforms; a straight rectangular wing and a rectangular wing with 60° swept tips. A final model, of a 60° delta wing, is currently being instrumented and will be tested in January 1996. Although the emphasis of the original proposal was on data collection, analysis of preliminary results has been presented at the European Rotorcraft Forum and a related paper is currently being reviewed for publication in a journal. The pressure data collected are of extremely high quality and are the most detailed of their type currently available. In addition, these have been supplement by extensive flow visualisation tests using a state of the art image capturing system. The resulting combined data set has highlighted many of the salient features of three-dimensional dynamic stall and, as originally intended, should provide a basis for future research in this area

Aerodynamic Design of Vertical Axis Wind Turbines. G.U. Aero Report 9246

This is the final report of research project GR/F 63466 on the Aerodynamic Design of Vertical Axis Wind Turbines. It is divided into two main sections. First, a general overview of the content, management and success of the work. Second, detailed technical information describing the design tools developed and experiments performed. Although the experimental programme, to test three appropriate aerofoil sections, had minor modification for reasons explained, three aerofoils were tested and the data distributed before archiving. Likewise, the proposed design code was subject to minor modification but a successful distorted wake model, including unsteady viscous effects, with typical run times well within designers requirements, was developed and is in current use. The package permits a wide range of blade designs that include taper, pitch, twist and change of aerofoil section along the span. The code has been delivered to Vertical Axis Wind Turbines Ltd

An Experimental and Numerical Study to Validate an Aerodynamic Model of Yawed Flow Over a Wind Turbine. Internal Report Number 9825

No abstract available

Wind Tunnel Investigations into the Air Flow around the Existing and Proposed Bridges at Kingston. G.U. Aero Report 9316

This report presents the results obtained from a series of flow visualisation and flow measurement wind tunnel tests, carried out at Glasgow University, on models of the existing and proposed Kingston bridges. The background to the tests, commissioned by Strathclyde Regional Council after discussions with staff from the Department of Aerospace Engineering, is provided in the Introduction. Details of the facilities employed and bridge representation are included also. The important experimental consideration of Similarity is addressed in some detail, with particular reference to the use of appropriate scaling parameters for flow frequencies and velocities in the vicinity of the bridges. Test results are presented firstly in the form of still photographs of the illuminated smoke traces, with the main features illustrated by the provision of flow diagrams for each test. Secondly, the more quantitative measurements are presented as graphs of velocity versus time at a variety of measuring stations. In addition, selected video records have been made and are available on an accompanying, indexed VHS cassette. A detailed discussion of the results is presented, and five main conclusions are made concerning the structure of the flow around the existing and proposed bridges

An Investigation of Three-Dimensional Dynamic Stall. G.U. Aero Report 9542

The following report summarises a three year research programme in the Department of Aerospace Engineering, University of Glasgow to collect unsteady pressure data on the dynamic stalling characteristics of finite wing planforms. The original motivation for the work lay in the pressing need for a greater understanding of the strongly three-dimensional effects in the tip region of helicopter rotors. In this study, a new data collection system capable of sampling 200 parallel channels at up to 50kHz per channel has been developed. Additionally, a new support structure, actuation mechanism and hydraulic supply system was established for the test programme. Together, these new systems were used to conduct tests on two wing planforms; a straight rectangular wing and a rectangular wing with 60° swept tips. A final model, of a 60° delta wing, is currently being instrumented and will be tested in January 1996. Although the emphasis of the original proposal was on data collection, analysis of preliminary results has been presented at the European Rotorcraft Forum and a related paper is currently being reviewed for publication in a journal. The pressure data collected are of extremely high quality and are the most detailed of their type currently available. In addition, these have been supplement by extensive flow visualisation tests using a state of the art image capturing system. The resulting combined data set has highlighted many of the salient features of three-dimensional dynamic stall and, as originally intended, should provide a basis for future research in this area