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

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.

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

Journal of Physics Conference Series ◽

10.1088/1742-6596/2103/1/012206 ◽

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.

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

Acta Polytechnica ◽

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.

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Experimental Studies on Aerodynamic Characteristics of Pantograph System According to the Pantograph Cover Configurations for High Speed Train

2011 Joint Rail Conference ◽

10.1115/jrc2011-56110 ◽

2011 ◽

Author(s):

Yeongbin Lee ◽

Minho Kwak ◽

Kyu Hong Kim ◽

Dong-Ho Lee

Keyword(s):

Wind Tunnel ◽

High Speed ◽

Aerodynamic Drag ◽

Aerodynamic Force ◽

Experimental Studies ◽

Wind Tunnel Test ◽

Aerodynamic Characteristics ◽

Experimental Models ◽

High Speed Train ◽

Drag And Lift

In this study, the aerodynamic characteristics of pantograph system according to the pantograph cover configurations for high speed train were investigated by wind tunnel test. Wind tunnel tests were conducted in the velocity range of 20∼70m/s with scaled experimental pantograph models. The experimental models were 1/4 scaled simplified pantograph system which consists of a double upper arm and a single lower arm with a square cylinder shaped panhead. The experimental model of the pantograph cover is also 1/4 scaled and were made as 4 different configurations. It is laid on the ground plate which modeled on the real roof shape of the Korean high speed train. Using a load cell, the aerodynamic force such as a lift and a drag which were acting on pantograph system were measured and the aerodynamic effects according to the various configurations of pantograph covers were investigated. In addition, the total pressure distributions of the wake regions behind the panhead of the pantograph system were measured to investigate the variations of flow pattern. From the experimental test results, we checked that the flow patterns and the aerodynamic characteristics around the pantograph systems are varied as the pantograph cover configurations. In addition, it is also found that pantograph cover induced to decrease the aerodynamic drag and lift forces. Finally, we proposed the aerodynamic improvement of pantograph cover and pantograph system for high speed train.

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

Proceedings of the Institution of Mechanical Engineers Part G Journal of Aerospace Engineering ◽

10.1177/0954410020926028 ◽

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.

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