Generation of Intake Distortion due to Angle of Attack for a High Bypass Turbofan Model

2014 ◽  
Author(s):  
Jan-Hendrik Krone ◽  
Jens Friedrichs
Keyword(s):  
Wind Tunnel ◽  
Angle Of Attack ◽  
Experimental Setup ◽  
Jet Engine ◽  
Numerical Investigations ◽  
Fan Performance ◽  
Aerodynamic Interaction ◽  
Inlet Conditions ◽  
The University ◽  
Operating Points

This article presents a new fan testing concept which was developed by the University of Braunschweig. The aim of the concept is to provide an experimental setup for integrated jet engine fan investigations. This integrated setup includes a full bypass model with nacelle geometry in order to obtain all aerodynamic interaction effects. Since these interactions have a strong dependency from fan inlet conditions the facility provides wind tunnel capacities. Generating both uniform and angle of attack inlet conditions it is possible to investigate fan performance during the most critical operating points of a civil flight mission. The main innovation of the wind tunnel is the crosswind concept for generating angle of attack conditions in case of a non-pitchable fan unit. Numerical investigations in this paper are intended to validate this new concept by means of typical angle of attack simulations. The results show that the crosswind concept is able to generate equivalent cp-characteristics as obtained for the reference simulations at the nacelle 6 o‘clock and 12 o‘clock positions.

Experimental Study of the Aerodynamic Interaction Between an Enclosed-Wheel Racing-Car and Its Rear Wing

1989 ◽  
Vol 111 (2) ◽  
pp. 154-159 ◽  
Author(s):  
J. Katz ◽  
R. Largman
Keyword(s):  
Experimental Study ◽  
Wind Tunnel ◽  
Ground Plane ◽  
Angle Of Attack ◽  
Lower Surface ◽  
Vehicle Body ◽  
Scale Model ◽  
Rear Wing ◽  
Aerodynamic Interaction ◽  
Tunnel Technique

A quarter-scale model of an enclosed wheel racing car was tested using the elevated ground plane wind tunnel technique. To increase the aerodynamic down force, two longitudinal underbody channels were built into the vehicle’s lower surface, and a rear wing was added. The effect of these underbody channels, and of wing angle of attack and position, on the vehicle’s drag and down force was experimentally investigated. Results of the experiments indicate that the flow under the car is affected by the presence of the wheels, and the vehicle without a rear wing generates only a negligible downforce. However, the addition of a rear wing enhanced the flow under the vehicle body, resulting in an increased aerodynamic downforce.

scholarly journals About the suitability of different numerical methods to reproduce model wind turbine measurements in a wind tunnel with high blockage ratio

2017 ◽  
Author(s):  
Annette Claudia Klein ◽  
Sirko Bartholomay ◽  
David Marten ◽  
Thorsten Lutz ◽  
George Pechlivanoglou ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Wind Turbine ◽  
Angle Of Attack ◽  
Flow Fields ◽  
Experimental Investigations ◽  
Far Field ◽  
Bending Moments ◽  
Validation Data ◽  
The University ◽  
Lifting Line

Abstract. Numerical and experimental investigations of a model wind turbine with a diameter of 3.0 m are described in the present paper. The objectives of the study are the provision of validation data, the comparison and evaluation of methods of different fidelity and the assessment of the influence of the wind tunnel walls by comparison of measurements to simulations with and without wind tunnel walls. The experiments were carried out in the large wind tunnel of the TU Berlin. With the Lifting Line Free Vortex Wake (LLFVW) code QBlade, the turbine was simulated under far field conditions at the TU Berlin. URANS simulations were performed at the University of Stuttgart with the CFD code FLOWer for far field condition to draw a comparison to QBlade. Moreover, CFD simulations of the turbine in a wind tunnel were carried out, as the walls have a significant influence on the turbine performance. Comparisons between experiment, the LLFVW code and CFD include on-blade velocities, angle of attack and bending moments. Comparisons of flow fields are drawn between experiment and the CFD code. A good accordance was achieved for the flow fields, the on-blade velocity and the angle of attack, whereas deviations occur for the bending moments.

Drag and Side Force Analysis on Bicycle Wheel–Tire Combinations

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Robert Crane ◽  
Chris Morton
Keyword(s):  
Wind Tunnel ◽  
Angle Of Attack ◽  
Force Transducer ◽  
Side Force ◽  
Wind Speeds ◽  
University Of Calgary ◽  
Strong Linear Correlation ◽  
Bicycle Racing ◽  
The University ◽  
Bicycle Wheel

Aerodynamic forces on bicycle racing wheels were investigated experimentally in a wind tunnel facility at the University of Calgary. The main geometric parameters investigated were the tire sidewall width, (21.40 mm≤T≤26.15 mm), rim depth, (55 mm≤D≤90 mm), rim width, (19.28 mm≤W≤25.75 mm), and angle of attack, (0deg≤ψ≤12.6deg). A total of six wheels and five tires were tested. Coefficient of drag area (CdA) and coefficient of side force area (CsA) versus angle of attack (ψ) were measured using a multi-axis force transducer. Wind tunnel conditions were set to simulate 2.94 m/s (6.6 mph) wind speeds and 13.4 m/s (30 mph) cyclist speeds. The performance of the wheel tire combinations was assessed using a wind-averaged drag method. The results show that the CdA of aerodynamic wheels is highly dependent on the wheel-tire combination. There is a strong linear correlation between wind averaged drag (CdA¯) and the ratio of the tire and rim width (T/W). The CsA of wheels is primarily controlled by the rim depth (D) and only weakly correlated with tire width (T).

Wind-tunnel experiments on the aerodynamic interaction between two rigid sails used for wind-assisted propulsion

2018 ◽  
Vol 65 (1) ◽  
pp. 93-125
Author(s):  
G. Bordogna ◽  
J.A. Keuning ◽  
R.H.M. Huijsmans ◽  
M. Belloli
Keyword(s):  
Wind Tunnel ◽  
Wind Tunnel Experiments ◽  
Aerodynamic Interaction

Experiences from the wind-tunnel testing of the Hardanger Bridge section model

2021 ◽  
Author(s):  
Bartosz Siedziako ◽  
Ole Øiseth
Keyword(s):  
Wind Tunnel ◽  
Superposition Principle ◽  
Higher Order ◽  
Lessons Learned ◽  
Order Effects ◽  
Experimental Setup ◽  
Wind Tunnel Testing ◽  
Section Model ◽  
Higher Order Effects ◽  
Tunnel Testing

<p>This paper presents an overview of the lessons learned and results from the extensive wind tunnel testing of the Hardanger bridge using a new experimental setup. Special attention is given to the reliability of wind tunnel results, the validity of the superposition principle, the presence of higher- order effects, and the importance of horizontal motion.</p>

Flutter Analysis of a Flexible UHBR Fan at Different Flight Conditions

2018 ◽  
Author(s):  
Matthias Schuff ◽  
Jannik Reisberg
Keyword(s):  
Aerodynamic Characteristics ◽  
Aeroelastic Stability ◽  
Aerodynamic Damping ◽  
Aerodynamic Loading ◽  
Similarity Principle ◽  
Flutter Analysis ◽  
Effective Angle ◽  
Inlet Conditions ◽  
Compressor Map ◽  
Operating Points

A flexible UHBR fan is investigated at different flight conditions with a focus on static deflections and aeroelastic stability. Operating points at varying inlet conditions, which are comparable according to the Mach similarity principle, are investigated. However, not all the aerodynamic characteristics remain identical and aerodynamic damping of mode shape vibrations is changed. When steady deformations of the fan blades are taken into account, the deviation between different inlet conditions increases further. This is mainly due to torsional deflections, changing the effective angle of attack and causing a general shift of the compressor map. Even though the subsequent changes in flutter predictions are not severe for most parts of the compressor map, the behavior at the boundaries is sensitive to the real flight condition. As shown, the Mach similarity principle is not suitable for investigating aeroelastic stability throughout the whole flight envelope, especially when the static blade deformation is not neglectable. The reason for this can be found in the complex interaction between dimension-less numbers (Mach, Reynolds), sized values (pressure difference or aerodynamic loading, natural frequency) and their dependency on each other.

scholarly journals A Simulation Study of Helicopter Ship Landing Procedures Incorporating Measured Flow-Field Data

2005 ◽  
Vol 219 (5) ◽  
pp. 411-427 ◽  
Author(s):  
D G Thomson ◽  
F Coton ◽  
R Galbraith
Keyword(s):  
Wind Tunnel ◽  
Wind Loading ◽  
Atmospheric Conditions ◽  
Wind Tunnel Tests ◽  
Inverse Simulation ◽  
Ship Model ◽  
Measured Flow ◽  
Wind Profiles ◽  
The University ◽  
Flight Deck

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.

Optimization Calculation of Javelin Throwing Results

2014 ◽  
Vol 716-717 ◽  
pp. 764-766
Author(s):  
Min Jiang ◽  
Ji He Zhou
Keyword(s):  
Mathematical Model ◽  
Wind Tunnel ◽  
Initial Velocity ◽  
Angle Of Attack ◽  
Wind Tunnel Experiment ◽  
Aerodynamic Efficiency ◽  
Optimization Calculation ◽  
Computer Optimization ◽  
Necessary And Sufficient

On the basis of javelin wind tunnel experiment, we established mathematical model of javelin flight to conduct a computer optimization and got the conclusions. When the initial velocity is in the range of 25m/s-30m/s, the best throwing condition is: the throwing angle is 40°, the angle of attack is 11°. The javelin throwing condition is not zero angle of attack was necessary and sufficient for obtained aerodynamic efficiency.

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