shockie
High Plains Rocketeer
According to this thread, up to about mach 0.39, an elliptical nose cone has the lowest drag:
https://www.rocketryforum.com/threads/elliptical-nose-cones-in-openrocket.174284/
This got me to thinking, would the same be true for an elliptical boat tail versus a conical taper or a cut off parabola.
I've read that angle of the boattail , a 5-6degree angle for a conical taper is generally good.
Does OR have the ability to choose the boat tail shape?
I did find this online;
Models, 7 calibers long, with a variety of conical, ogival convex and concave boattails were free-flight tested at M 1.70, for drag and other aerodynamic characteristics. The total drag decreases monotonically for boattails longer than 0.5 calibers. For shorter boattails, the drag is higher than that of the square based body. For boattail lengths between 0.5 and 1.5 calibers, conical boattails have lower drag than either the ogival or concave configurations. The base pressure decreases with boattail length but increases with the boattail angle at the base. Among other aerodynamic characteristics, the boattailing appears to cause the most significant change in the Magnus torque coefficient. For certain boattails, this change may be sufficiently large to make the configuration dynamically unstable.
https://www.rocketryforum.com/threads/elliptical-nose-cones-in-openrocket.174284/
This got me to thinking, would the same be true for an elliptical boat tail versus a conical taper or a cut off parabola.
I've read that angle of the boattail , a 5-6degree angle for a conical taper is generally good.
Does OR have the ability to choose the boat tail shape?
I did find this online;
Models, 7 calibers long, with a variety of conical, ogival convex and concave boattails were free-flight tested at M 1.70, for drag and other aerodynamic characteristics. The total drag decreases monotonically for boattails longer than 0.5 calibers. For shorter boattails, the drag is higher than that of the square based body. For boattail lengths between 0.5 and 1.5 calibers, conical boattails have lower drag than either the ogival or concave configurations. The base pressure decreases with boattail length but increases with the boattail angle at the base. Among other aerodynamic characteristics, the boattailing appears to cause the most significant change in the Magnus torque coefficient. For certain boattails, this change may be sufficiently large to make the configuration dynamically unstable.