Transonic Aerodynamics
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Transonic Airfoil Characteristics | |
There are two pages on airfoil characteristics. this one is about transonic characteristics and the effect of Mach number. The other is "Reynolds Number Effect". These graphs adapted from R. T. Jones' Wing Theory shows airfoil characteristics as measured in a wind tunnel. the lift curve slope also shows the predictions of linearized theory. The close agreement supports the use of linearized theory as used here in modifying pitch distribution Note that the lift curve slope rises with Mach Number. This means that a LOWER angle of attack is required. The program correctly accounts for this effect. The lower curve "zero lift drag" is the minimum drag that will be produced. Note how important it is to keep sections thin at high Mach numbers. The program computes the Mach number at each blade station. If the application is for very high engine speeds, such as F2A, then close attention needs to be paid to the thickness at the tip. Use this figure as a guide for how thin the blade should be at the tip. |