scholarly journals Features of flow around transport aircraft model with running propellers by modelled engine failure in wind tunnel

2021 ◽  
Vol 2103 (1) ◽  
pp. 012206
Author(s):  
V I Chernousov ◽  
A A Krutov ◽  
E A Pigusov
Keyword(s):  
Wind Tunnel ◽  
Lift Coefficient ◽  
Aerodynamic Characteristics ◽  
Light Transport ◽  
Transport Aircraft ◽  
Engine Failure ◽  
The One ◽  
Low Speed Wind Tunnel ◽  
Control Surfaces ◽  
Landing Mode

Abstract This paper presents the experiment results of modelling the one engine failure at the landing mode on a model of a light transport airplane in the T-102 TsAGI low speed wind tunnel. The effect of starboard and port engines failure on the aerodynamic characteristics and stability of the model is researched. The model maximum lift coefficient is reduced about ≈8% and there are the same moments in roll and yaw for starboard and port engines failure case. It was found that the failure of any engine has little impact on the efficiency of control surfaces. Approaches of compensation of forces and moments arising in the engine failure case were investigated.

scholarly journals Development of a Technique and Method of Testing Aircraft Models with Turboprop Engine Simulators in a Small-scale Wind Tunnel - Results of Tests

10.14311/530 ◽  
2004 ◽  
Vol 44 (2) ◽  
Author(s):  
A. V. Petrov ◽  
Y. G. Stepanov ◽  
M. V. Shmakov
Keyword(s):  
Wind Tunnel ◽  
Aerodynamic Characteristics ◽  
Static Stability ◽  
Light Transport ◽  
Experimental Investigations ◽  
Small Scale ◽  
Left Hand ◽  
Aircraft Model ◽  
Turboprop Engine ◽  
Control Surfaces

This report presents the results of experimental investigations into the interaction between the propellers (Ps) and the airframe of a twin-engine, twin-boom light transport aircraft with a Π-shaped tail. An analysis was performed of the forces and moments acting on the aircraft with rotating Ps. The main features of the methodology for windtunnel testing of an aircraft model with running Ps in TsAGI’s T-102 wind tunnel are outlined.The effect of 6-blade Ps slipstreams on the longitudinal and lateral aerodynamic characteristics as well as the effectiveness of the control surfaces was studied on the aircraft model in cruise and takeoff/landing configurations. The tests were conducted at flow velocities of V∞ = 20 to 50 m/s in the ranges of angles of attack α =  -6 to 20 deg, sideslip angles of β = -16 to 16 deg and blade loading coefficient of B 0 to 2.8. For the aircraft of unusual layout studied, an increase in blowing intensity is shown to result in decreasing longitudinal static stability and significant asymmetry of the directional stability characteristics associated with the interaction between the Ps slipstreams of the same (left-hand) rotation and the empennage.

scholarly journals Analysis of the propellers-airframe interaction of the light transport aircraft

2021 ◽  
Vol 24 (5) ◽  
pp. 76-88
Author(s):  
Yu. S. Mikhailov
Keyword(s):  
Wind Tunnel ◽  
Experimental Studies ◽  
Aerodynamic Characteristics ◽  
High Energy ◽  
Light Transport ◽  
Transport Aircraft ◽  
High Energy Level ◽  
Combined Use ◽  
Wind Tunnel Balance ◽  
Propeller Blades

In the design of multi-engine aircraft, one of the important issues is the interaction between the propellers and airframe configuration components, especially in take-off and go-around procedure modes. Modern propeller-driven aircraft concepts in the pulling configuration are characterized by a high disk loading and an increased number of propeller blades used to increase cruising speed and reduce excessive noise. The first problem arising due to high disk loading is the direct impact of forces by operating propellers (thrust, normal force) on fixed-wing stability, especially at angles of attack different from a zero value. The second one involves a high-energy level of the propeller slipstream, having a significant indirect impact on the aircraft’s aerodynamics, stability and controllability. This impact is primarily associated with the interaction of propellers slipstream with other aircraft’s configuration elements. The complexity of taking into account the slipstream-wing interaction and other airframe components stipulated the application of experimental methods to study the problems of propellers – airframe interaction while designing propeller-driven aircraft configurations. This article presents an analysis of the experimental studies results of the operating propellers- airframe interaction for a light twin-engine transport aircraft. The aerodynamic aircraft’s configuration is executed using the conventional pattern of a high-wing and the carrier-on deck type empennage. The high-lift wing device is a fixed-vane doubleslotted flap. The wind-tunnel tests of the model in the cruising, takeoff and landing configurations were carried out in TsAGI lowspeed wind-tunnel T-102. Measurement of forces and moments, acting on the model, was performed by means of an external sixcomponent wind-tunnel balance. Measurement of forces and moments, acting on the propeller, was conducted using strain gauge weighers installed inside the engine nacelles of power plant simulators. The simultaneous combined use of external and internal balances allowed researchers to determine the direct and indirect contribution of operating propellers to the model longitudinal aerodynamic characteristics under variation of loading factor B ranging from 0 to 2.

Optimization of the three-segment aerofoil arrangement based on wind tunnel tests and numerical analysis

2020 ◽  
pp. 095441002092602
Author(s):  
Wojciech Grendysa ◽  
Bartosz Olszański
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Tunnel ◽  
Response Surface ◽  
Lift Coefficient ◽  
Light Transport ◽  
Optimization Approach ◽  
Wind Tunnel Tests ◽  
Transport Aircraft ◽  
Aerodynamic Configuration

This paper presents the optimization of multi-element aerofoil for the LAR-3 Puffin -- STOL light transport aircraft concept proposal. Based on the geometry and aerodynamic characteristics of the well-known and proven in flight three-segment NACA 63A416 aerofoil, the authors explore the possibility of enhancing its high-lift performance by the movement of slot and flap position in extended (deployed) aerodynamic configuration. In order to determine the optimum positions of aerofoil segments (elements), a multi-step optimization approach was developed. It combines computational fluid dynamics simulations that were used for design space screening and preliminary optimization together with low-turbulence wind tunnel tests which yielded certain results. To decrease the numerical cost of the computer simulation campaign, Design of experiment methods (optimal space-filling design among others) were employed instead of exhausting full factorial (parametric) design. Response surface models of major aerodynamic coefficients (lift, drag, pitching moment) at predicted maximum lift coefficient ( C L max) point allowed to narrow down search space and identify several candidates for optimal configuration to be checked experimentally. Wind tunnel tests campaign confirmed the major trends observed in computational fluid dynamics derived response surface contour plots. For the optimum aerodynamic configuration, chosen experimental C L max is over 3.9, which is a 10% increase over the baseline (initial slat and flap positions) case. In parallel, the maximum lift-to-drag ratio gain at that point was almost 19%. The research outlined in this paper was conducted on behalf of the aircraft production company and its results will be applied in a newly designed transport aircraft.

Aerodynamics of Gliding Flight in a Falcon and Other Birds

1970 ◽  
Vol 52 (2) ◽  
pp. 345-367 ◽  
Author(s):  
VANCE A. TUCKER ◽  
G. CHRISTIAN PARROTT
Keyword(s):  
Wind Tunnel ◽  
High Performance ◽  
Lift Coefficient ◽  
Aerodynamic Characteristics ◽  
Wing Span ◽  
Technical Errors ◽  
Gliding Flight ◽  
Air Speed ◽  
D Values ◽  
D Value

1. A live laggar falcon (Falco jugger) glided in a wind tunnel at speeds between 6.6 and 15.9 m./sec. The bird had a maximum lift to drag ratio (L/D) of 10 at a speed of 12.5 m./sec. As the falcon increased its air speed at a given glide angle, it reduced its wing span, wing area and lift coefficient. 2. A model aircraft with about the same wingspan as the falcon had a maximum L/D value of 10. 3. Published measurements of the aerodynamic characteristics of gliding birds are summarized by presenting them in a diagram showing air speed, sinking speed and L/D values. Data for a high-performance sailplane are included. The soaring birds had maximum L/D values near 10, or about one quarter that of the sailplane. The birds glided more slowly than the sailplane and had about the same sinking speed. 4. The ‘equivalent parasite area’ method used by aircraft designers to estimate parasite drag was modified for use with gliding birds, and empirical data are presented to provide a means of predicting the gliding performance of a bird in the absence of wind-tunnel tests. 5. The birds in this study had conventional values for parasite drag. Technical errors seem responsible for published claims of unusually low parasite drag values in a vulture. 6. The falcon adjusted its wing span in flight to achieve nearly the maximum possible L/D value over its range of gliding speeds. 7. The maximum terminal speed of the falcon in a vertical dive is estimated to be 100 m./sec.

Aerodynamic Characteristics of a Deformable Membrane Aerofoil

2014 ◽  
Vol 553 ◽  
pp. 255-260
Author(s):  
Viktor Šajn ◽  
Igor Petrović ◽  
Franc Kosel
Keyword(s):  
Experimental Study ◽  
Reynolds Number ◽  
Wind Tunnel ◽  
Lift Coefficient ◽  
Fluid Structure Interaction ◽  
Angle Of Attack ◽  
Aerodynamic Characteristics ◽  
Relative Difference ◽  
Structure Interaction ◽  
Deformable Membrane

In the paper, numerical and experimental study of low Reynolds number airflow around the deformable membrane airfoil (DMA) is presented. Simulations of a fluid-structure interaction between the fluid and the DMA were performed. In the experiment, the DMA model was made from a thin PVC sheet, which was wrapped around the steel rod at the leading and trailing edge. Measurements were performed in a wind tunnel at a chord Reynolds number of 85.7·103, over the angle of attack range from 0° to 15° and DMA shortening ratio from 0.025 to 0.150. Simulations were in an agreement with the experiment, since the average relative difference of coefficient of lift was smaller than 7.3%. For the same value of Reynolds number, DMA shows improved lift coefficient Cy= 2.18, compared to standard rigid airfoils.

Wind Tunnel Experimental Study of Wind Turbine Airfoil Aerodynamic Characteristics

2012 ◽  
Vol 260-261 ◽  
pp. 125-129
Author(s):  
Xin Zi Tang ◽  
Xu Zhang ◽  
Rui Tao Peng ◽  
Xiong Wei Liu
Keyword(s):  
Wind Tunnel ◽  
Wind Turbine ◽  
Lift Coefficient ◽  
Turbine Blades ◽  
Aerodynamic Characteristics ◽  
Wind Turbine Blades ◽  
High Lift ◽  
Minimum Drag ◽  
Stall Angle ◽  
High Reynolds

High lift and low drag are desirable for wind turbine blade airfoils. The performance of a high lift airfoil at high Reynolds number (Re) for large wind turbine blades is different from that at low Re number for small wind turbine blades. This paper investigates the performance of a high lift airfoil DU93-W-210 at high Re number in low Re number flows through wind tunnel testing. A series of low speed wind tunnel tests were conducted in a subsonic low turbulence closed return wind tunnel at the Re number from 2×105to 5×105. The results show that the maximum lift, minimum drag and stall angle differ at different Re numbers. Prior to the onset of stall, the lift coefficient increases linearly and the slope of the lift coefficient curve is larger at a higher Re number, the drag coefficient goes up gradually as angle of attack increases for these low Re numbers, meanwhile the stall angle moves from 14° to 12° while the Re number changes from 2×105to 5×105.

The Effect of Canard to the Aerodynamic Behavior of Blended Wing Body Aircraft

2012 ◽  
Vol 225 ◽  
pp. 38-42
Author(s):  
Zurriati Mohd Ali ◽  
Wahyu Kuntjoro ◽  
Wisnoe Wirachman
Keyword(s):  
Mach Number ◽  
Wind Tunnel ◽  
Aerodynamic Characteristic ◽  
Lift Coefficient ◽  
Aerodynamic Characteristics ◽  
Moment Coefficient ◽  
Subsonic Wind Tunnel ◽  
Setting Angle ◽  
Blended Wing Body ◽  
The Moment

This paper presents a study on the effect of canard setting angle on the aerodynamic characteristic of a Blended Wing Body (BWB). Canard effects to BWB aerodynamic characteristics are not widely investigated. Hence the focus of the study is to investigate the variations of lifts, drags and moments when the angles of attack are varied at different canard setting angles. Wind tunnel tests were performed on BWB aircraft with canard setting angles,  ranging from -20˚ to 20˚. Angles of attack,  were varied from -10˚ to 10˚. Aspect ratio and canard planform area were kept fixed. All tests were conducted in the subsonic wind tunnel at Universiti Teknologi MARA, at Mach number of 0.1. The streamlines flow, at the upper surface of the canard was visualized using mini tuft. Result shows that the lift coefficient does not change much with different canard setting angles. As expected, the lift coefficient increases with increasing angles of attack at any canard setting angle. In general, the moment coefficient increases as the canard setting angle is increased. The results obtained in this research will be of importance to the understanding of aerodynamic behavior of BWB employing canard in its configuration.

scholarly journals Experimental Study on Aerodynamic Characteristics of a Gurney Flap on a Wind Turbine Airfoil under High Turbulent Flow Condition

2020 ◽  
Vol 10 (20) ◽  
pp. 7258 ◽  
Author(s):  
Junwei Yang ◽  
Hua Yang ◽  
Weijun Zhu ◽  
Nailu Li ◽  
Yiping Yuan
Keyword(s):  
Wind Tunnel ◽  
Turbulent Flow ◽  
Lift Coefficient ◽  
Leading Edge ◽  
Aerodynamic Characteristics ◽  
Chord Length ◽  
Turbulence Level ◽  
Gurney Flaps ◽  
Gurney Flap ◽  
Delay Phenomenon

The objective of the current work is to experimentally investigate the effect of turbulent flow on an airfoil with a Gurney flap. The wind tunnel experiments were performed for the DTU-LN221 airfoil under different turbulence level (T.I. of 0.2%, 10.5% and 19.0%) and various flap configurations. The height of the Gurney flaps varies from 1% to 2% of the chord length; the thickness of the Gurney flaps varies from 0.25% to 0.75% of the chord length. The Gurney flap was vertical fixed on the pressure side of the airfoil at nearly 100% measured from the leading edge. By replacing the turbulence grille in the wind tunnel, measured data indicated a stall delay phenomenon while increasing the inflow turbulence level. By further changing the height and the thickness of the Gurney flap, it was found that the height of the Gurney flap is a very important parameter whereas the thickness parameter has little influence. Besides, velocity in the near wake zone was measured by hot-wire anemometry, showing the mechanisms of lift enhancement. The results demonstrate that under low turbulent inflow condition, the maximum lift coefficient of the airfoil with flaps increased by 8.47% to 13.50% (i.e., thickness of 0.75%), and the Gurney flap became less effective after stall angle. The Gurney flap with different heights increased the lift-to-drag ratio from 2.74% to 14.35% under 10.5% of turbulence intensity (i.e., thickness of 0.75%). However, under much a larger turbulence environment (19.0%), the benefit to the aerodynamic performance was negligible.

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