33 research outputs found
Drag Interference Between a Pointed Cylindrical Body and Triangular Wings of Various Aspect Ratios at Mach Numbers of 1.50 and 2.02
The drag of a body alone, six triangular wings of various aspect ratios, and the combinations were measured at Mach numbers of 1.50 and 2.02 at a Reynolds number of 5.5 million (based on the body length). The experimental drag-interference results were in accordance with calculations based on NACA RM A9E19, 1949, with skin-friction effects taken into account, the interference effect being principally the result of fixing transition on the body by adding a wing
Atmosphere Entries with Vehicle Lift-Drag Ratio Modulated to Limit Deceleration and Rate of Deceleration: Vehicles with Maximum Lift-Drag Ratio of 0.5
An analysis has been made of atmosphere entries for which the vehicle lift-drag ratio was modulated to maintain specified maximum decelerations and/or maximum deceleration rates. The part of the vehicle drag polar used during modulation was from maximum lift coefficient to minimum drag coefficient. The entries were at parabolic velocity and the vehicle maximum lift-drag ratio was 0.5. Two-dimensional trajectory calculations were made for a nonrotating, spherical earth with an exponential atmosphere. The results of the analysis indicate that for a given initial flight-path angle, modulation generally resulted in a reduction of the maximum deceleration to 60 percent of the unmodulated value or a reduction of maximum deceleration rate to less than 50 percent of the unmodulated rate. These results were equivalent, for a maximum deceleration of 10 g, to lowering the undershoot boundary 24 miles with a resulting decrease in total convective heating to the stagnation point of 22 percent. However, the maximum convective heating rate was increased 18 percent; the maximum radiative heating rate and total radiative heating were each increased about 10 percent
Lift and Pitching-moment Interference Between a Pointed Cylindrical Body and Triangular Wings of Various Aspect Ratios at Mach Numbers of 1.50 and 2.02
The lift and pitching-moment characteristics of a body alone, six triangular wings of various aspect ratios, and the combinations were measured at Mach numbers of 1.50 and 2.02 at a Reynolds number of 5.5 million (based on the body length) for angles of attack up to 5.5 degrees. The total lift and pitching-moment interference were determined and compared with theory. The agreement was found to be good
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NACA Technical Notes
Report presenting the theoretical possibilities for obtaining high lift-drag ratios at M = 3 and to describe some experiments designed to exploit the theory. Relatively high lift-drag ratios calculated were partly realized at low wind-tunnel Reynolds numbers. The rate of increase in maximum lift-drag ratio with increased Reynolds number was greater than expected, which indicated a need for more experiments at conditions closer to actual flight