Measurement of Steady and Unsteady Pressures on a Wing/Engine Combination including Jet Simulation in Subsonic Flow.

Experimental investigations on the steady and unsteady aerodynamic forces were performed on a wing/ejector engine model in the subsonic flow regime. The pressure measurements were made for the following parameters velocity, angle of attack, mass flow, reduced frequency, and amplitude of oscillation of the engine performing pitch oscillations. For the wing/engine combination, the unsteady interference effects for engine oscillation on the pressure side of the wing are strongly affected by flow separation at the wing/pylon connection. The induced unsteady aerodynamic forces on the wing are small. The experimental results are ready to be compared with theories, which still must be developed for all necessary parameters.Problems with the test models, the test equipment, the measuring procedure, and the electronic data recording and processing are discussed

Measurement of Unsteady Pressures and Forces on an Engine and a Wing/Engine Combination Including Jet Simulation.

Experimental investigations on the unsteady aerodynamic forces were performed on an ejector engine model and a wing/engine combination in the subsonic and transonic flow regimes. The experimental results were compared to theoretical results. The aim was to determine how well the commonly used mathematical aerodynamic models for flutter calculations correspond to the actual relationships observed on engines. The investigations on the ejector engine demonstrated that linear lifting surface theory provides accurate unsteady aerodynamic forces. The effects of Mach number and reduced frequency are described correctly. For the wing/engine combination, the unsteady interference effect for engine oscillation on the lower side of the wing is strongly influenced by flow separation at the wing/pylon connection. In general, the unsteady aerodynamic forces on the wing are small and, at this order of magnitude, can be correctly calculated with the linear lifting surface theory

Measurement of Unsteady Airloads on an Oscillating Engine and a Wing-Engine Combination.

Experimental investigations of unsteady aerodynamic forces were performed on an oscillating ejector engine model and a wing/engine combination in the subsonic and transonic flow regimes. The experimental results were compared with theoretical results. The aim was to determine how well, in reality, the mathematical aerodynamic models commonly used for flutter calculations correspond to the flow conditions on an engine. The investigations on the isolated ejector engine demonstrated that linear lifting surface theory provides quite accurate unsteady aerodynamic forces. The effects of the Mach number and reduced frequency are described correctly. For the wing/engine combination, the unsteady interference effect of the engine oscillation on the lower side of the wing is strongly influenced by flow separation at the wing/pylon connection. In general, the unsteady aerodynamic forces induced by the engine on the wing are small and are therefore of minor influence on the unsteady airloads of an oscillating wing

Instationaere Aerodynamik schnellbewegter Klappen und Spoiler fuer die aktive Steuerung zur Minderung von Boeen und Manoeverlasten

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