Practical Ways to Study Flutter
The process requires two sides the Experimental and the numerical:
The following wing flutter test shown is a cheap way to show the destructive behavior flutter has at certain flight conditions. It is noticeable how the aeroloins at some point start fluttering after there connecting mechanism breaks.
Applying flow controlling vanes ahead of the flow stream applies flow instabilities (Turbulence) these instabilities are magnified in magnitude as they are further downstream till they reach the studied model. Using the springs is done to represent the pilots in stabilizing the aircraft flight condition to a steady one response or the turbulence the plane flies through. The video shows that the use of wind tunnel trials to calculate the generated lift at these flow conditions, in addition to measure the maximum force the wing fittings with the main aircraft fuselage encounter and their layout distribution and if there is a need for a set of 6 or 8. The number 4 is unfavorable due to safety regulations.
Aeroelastic effects on rotating turbines. Predicting Propeller whirl activity is essential in order to identify on the rotating shaft of the propeller where the maximum momentum and shear stress is occurring meaning that either an increase is shaft diameter is applicable of the increase of the number of used ball bearings stages it is common that three stages are used in turboprop engines.
I presume for now you’re starting point will be for now your wind tunnel experiments. Then the captured data on how the wing structure would flutter (vibrate) at the studied flight conditions comes of importance, where data curve fitting and interpolation is required. Next comes formulating the mathematical model on the wing structure and applying the same wind tunnel flight conditions. You will have to see the effects of the generated lift at each section of the wing .The generated output data from the model is compared to your experiments and from there you can validate your model.
Wind tunnel flutter tests, by increasing the blowing speeds and recording the response of the aircraft winds the frequency of wing vibration can be extracted in addition to the maximum value of deflection. The same procedure can be applied for the aircraft tail section, the main concern for studying the rear wing is to see cross wind effects. It is visible how these kinds of vibration occur near the aircraft wing tips. This helps in finding the regions of the structure that needs strengthening at the same time taking into account the price of that kind of modification cost and weight wise.
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