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1 – 4 of 4Andrzej Krzysiak, Robert Placek, Aleksander Olejnik and Łukasz Kiszkowiak
The main purpose of this study was to determine the basic aerodynamic characteristics of the airliner Tu-154M at the wide range of the overcritical angles of attack and sideslip…
Abstract
Purpose
The main purpose of this study was to determine the basic aerodynamic characteristics of the airliner Tu-154M at the wide range of the overcritical angles of attack and sideslip angles, i.e. α = −900° ÷ 900° and β = −900° ÷ 900°.
Design/methodology/approach
Wind tunnel tests of the Tu-154M aircraft model at the scale 1:20 were performed in a low-speed wind tunnel T-3 by using a six-component internal aerodynamic balance. Several model configurations were also investigated.
Findings
The results of the presented studies showed that at the wide range of the overcritical angles of attack and sideslip angles, i.e. α = −900° ÷ 900° and β = −900° ÷ 900°, the Tu-154M aircraft flap deflection affected the values of the drag and lift coefficients and generally had no major effect on the values of the side force and pitching moment coefficients.
Research limitations/implications
The model vibration which was the result of flow separation at high angles of attack was the wind tunnel test limitation.
Practical implications
Studies of the airliner aerodynamic characteristics at the wide range of the overcritical angles of attack and sideslip angles allow assessment of the aircraft aerodynamic properties during possible unexpected situations when the passenger aircraft is found to have gone beyond the conventional flight envelope.
Social implications
There are no social implications of this study to report.
Originality/value
The presented wind tunnel test results of the airliner aerodynamic characteristics at overcritical angles of attack and sideslip angles is an original contribution to the existing not-too-extensive database available in the literature.
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Andrzej Krzysiak, Dawid Cieśliński, Robert Placek and Pawel Kekus
The purpose of this study is to determine the impact of two parallel boosters fixed to the ILR 33 AMBER 2 K core rocket stage on its aerodynamic characteristics in the subsonic…
Abstract
Purpose
The purpose of this study is to determine the impact of two parallel boosters fixed to the ILR 33 AMBER 2 K core rocket stage on its aerodynamic characteristics in the subsonic and transonic regimes and for M = 2.3.
Design/methodology/approach
Wind tunnel tests of the rocket model were carried out in a trisonic wind tunnel using a six-component internal balance. Three rocket model configurations were investigated.
Findings
The results of the presented studies showed that the presence of boosters causes a significant increase in the total rocket drag, which depends on both the Mach number and the rocket flight phase. Experimental tests of the rocket model allowed to determine the difference in drag coefficient between active and passive flight versus Mach number. It was found that, in the case of a deviation from the rocket’s flight direction, the aerodynamic coefficients strongly depend on the location of the boosters in relation to the direction of the deviation.
Practical implications
Studies of the rocket model aerodynamic characteristics allow the assessment of the influence of parallel boosters on rocket performance, which is important when the decision of a rocket staging type is taken.
Originality/value
The presented wind tunnel test results of the rocket model equipped with the two parallel boosters are an original contribution to the rocket research results presented in the literature.
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Wienczyslaw Stalewski and Andrzej Krzysiak
The purpose of this study is to develop the concept of self-adapting system which would be able to control a flow on the wing-high-lift system and protect the flow against strong…
Abstract
Purpose
The purpose of this study is to develop the concept of self-adapting system which would be able to control a flow on the wing-high-lift system and protect the flow against strong separation.
Design/methodology/approach
The self-adapting system has been developed based on computational approach. The computational studies have been conducted using the URANS solver. The experimental investigations have been conducted to verify the computational results.
Findings
The developed solution is controlled by closed-loop-control (CLC) system. As flow actuators, the main-wing trailing-edge nozzles are proposed. Based on signals received from the pressure sensors located at the flap trailing edge, the CLC algorithm changes the amount of air blown from the nozzles. The results of computational simulations confirmed good effectiveness and reliability of the developed system. These results have been partially confirmed by experimental investigations.
Research limitations/implications
The presented research on an improvement of the effectiveness of high-lift systems of modern aircraft was conducted on the relatively lower level of the technology readiness. However, despite this limitation, the results of presented studies can provide a basis for developing innovative self-adaptive aerodynamic systems that potentially may be implemented in future aircrafts.
Practical implications
The studies on autonomous flow-separation control systems, operating in a closed feedback loop, are a great hope for significant advances in modern aeronautical engineering, also in the UAV area. The results of the presented studies can provide a basis for developing innovative self-adaptive aerodynamic systems at a higher level of technological readiness.
Originality/value
The presented approach is especially original and valuable in relation to the innovative concept of high-lift system supported by air-jets blown form the main-wing-trailing-edge nozzles; the effective and reliable flow sensors are the pressure sensors located at the flap trailing edge, and the effective and robust algorithm controlling the self-adapting aerodynamic system – original especially in respect to a strategy of deactivation of flow actuators.
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Spiros Pantelakis, Andreas Strohmayer and Jordi Pons Prats