Natural laminar flow - A wind tunnel test campaign and comparison with flight test data

1990 ◽  
Author(s):  
A. QUAST ◽  
R. HENKE ◽  
F. MUENCH
Keyword(s):  
Wind Tunnel ◽  
Laminar Flow ◽  
Test Data ◽  
Wind Tunnel Test ◽  
Flight Test ◽  
Natural Laminar Flow

Qualification of the ARA TWT for laminar flow testing

2014 ◽  
Vol 118 (1209) ◽  
pp. 1349-1358 ◽  
Author(s):  
N. Allen ◽  
S. Lawson ◽  
M. Maina ◽  
J. Alderman
Keyword(s):  
Wind Tunnel ◽  
Laminar Flow ◽  
Large Scale ◽  
Wind Tunnel Test ◽  
Performance Testing ◽  
Current Drive ◽  
Future Research ◽  
Temperature Sensitive ◽  
Tollmien Schlichting ◽  
Natural Laminar Flow

Abstract The current drive towards reducing the environmental impact of aircraft necessitates the ability to evaluate techniques for promoting natural laminar flow in a large scale wind tunnel facility. A test was undertaken on the M2355 variable sweep model to obtain temperature sensitive paint (TSP) and hot-film data from which the transition locations at a range of sweep angles and flow conditions could be identified. The TSP technique has been shown to be a reliable method for determining transition on suitably treated wind tunnel models. Pressure data were also acquired and interpolated to provide the input to the laminar boundary layer code, BL2D, the output from which was used in the linear stability analysis code, CoDS, to calculate the N-factor for the ARA TWT (Transonic Wind Tunnel) facility. Two sets of N-factors were calculated, firstly using incompressible analysis with stationary crossflow and secondly using compressible analysis with travelling crossflow. In both analyses the Tollmien-Schlichting and crossflow cases were calculated together, rather than separating the cases before running the analysis. The resulting N-factors indicate a degree of scatter typical for experimental data. The N-factor based on incompressible theory for crossflow was found to be approximately 7 and for Tollmien-Schlichting (T-S), approximately 11. The results of the wind tunnel test and the analysis carried out are considered to be the first steps towards establishing a methodology for performance testing, in atmospheric tunnels such as the TWT, for aircraft designed to have significant regions of laminar flow. The project has also provided a body of experimental test data which will be valuable for future research into development and validation of laminar flow methods.

scholarly journals Design and Performance Evaluation of Propeller for Solar-Powered High-Altitude Long-Endurance Unmanned Aerial Vehicle

2018 ◽  
Vol 2018 ◽  
pp. 1-23 ◽  
Author(s):  
Donghun Park ◽  
Yunggyo Lee ◽  
Taehwan Cho ◽  
Cheolwan Kim
Keyword(s):  
Wind Tunnel ◽  
High Altitude ◽  
Test Data ◽  
Design Method ◽  
Wind Tunnel Test ◽  
Flight Test ◽  
Cfd Analysis ◽  
Aerial Vehicle ◽  
Solar Powered ◽  
Long Endurance

Design, wind tunnel test, computational fluid dynamics (CFD) analysis, and flight test data analysis are conducted for the propeller of EAV-3, which is a solar-powered high-altitude long-endurance unmanned aerial vehicle developed by Korea Aerospace Research Institute. The blade element momentum theory, in conjunction with minimum induced loss, is used as a basic design method. Airfoil data are obtained from CFD analysis, which takes into account the low Reynolds number effect. The response surface is evaluated for design variables by using design of experiment and kriging metamodel. The optimization is based on desirability function. A wind tunnel test is conducted on the designed propeller. Numerical analyses are performed by using a commercial CFD code, and results are compared with those obtained from the design code and wind tunnel test data. Flight test data are analyzed based on several approximations and assumptions. The propeller performance is in good agreement with the numerical and measurement data in terms of tendency and behavior. The comparison of data confirms that the design method, wind tunnel test, and CFD analysis used in this study are practically useful and valid for the development of a high-altitude propeller.

The Flight Testing of Natural and Hybrid Laminar Flow Nacelles

1994 ◽  
Author(s):  
Brian Barry ◽  
Simon J. Parke ◽  
Nicholas W. Bown ◽  
Hansgeorg Riedel ◽  
Martin Sitzmann
Keyword(s):  
Boundary Layer ◽  
Laminar Flow ◽  
Aircraft Engine ◽  
Flight Test ◽  
Boundary Layer Transition ◽  
Future Application ◽  
Flight Testing ◽  
Layer Transition ◽  
Suction System ◽  
Natural Laminar Flow

The achievement of large areas of laminar flow over aircraft engine nacelles offers significant savings in aircraft fuel consumption. Based upon current engine configurations nett sfc benefits of up to 2% are possible. In addition the engine nacelle is ideally suited to the early inclusion of laminar flow technology, being relatively self contained with the possibility of application to existing airframes. In September 1992 a European Consortium managed by Rolls-Royce including MTU and DLR began flight testing of a natural laminar flow nacelle. This programme was later extended by R-R and DLR to flight test a hybrid laminar flow nacelle featuring boundary layer suction and insect contamination protection. The tests evaluated the effects of flight and engine environment, boundary layer transition phenomena, suction system operation and insect contamination avoidance strategies. This paper describes the global conclusions from these flight tests which are a significant milestone leading to the future application of laminar flow technology to engine nacelles.

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