Rocket Modeling
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Last update - 06 November 1998
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Posted by: phenix, The Haze F/B Group

Posted on: 22:35:38 11/05/98

Message:

I noticed this the other night while practicing offline and wondered if it may be a bug. In the picture above, I went full rudder and into a skid. I then fired all my rockets, but the rockets went in the direction of flight rather than direction of the nose. Wouldn't rockets fire in the direction the plane was pointed, like bullets? Or will their fins point them in the direction of travel upon release? Whatever the answer this is a definite change from the last version. You must now aim rockets with the slip(or whatever it is) indicator in the HUD rather than the gunsight. Having a physics degree, I believe this is wrong.

I sent a message through the tech webpage at IMOL, but then wondered if maybe its doing what its supposed to or maybe I missed reading about it.

Is this just me or anyone else having this problem? I haven't tested it online yet, but I think rockets are modeled on the FE anyway...

Troy"phenix"Errthum

Posted by: Thog

Posted on: 00:58:10 11/06/98

Message: >Wouldn't rockets fire in the direction the plane was pointed, like >bullets? Or will their fins point them in the direction of travel >upon release

They would snap to point in the direction of the airstream. The fins would heel around untill they weren't getting lateral resistance. This is the same effect that causes problems for Fin-Stabilized-Discarding-Sabot rounds. In a crosswind, the APFSDS round will turn into the wind (rather than away from it, as my first mental glance would have indicated), causing the round to go off course. A spin-stabilized round (without fins) won't do this; I believe because the pressure is more even across the body of the object, rather than exaggerated on one area (the fins). I believe modern Fire-Control systems in the M1A1 and equavalent AFV's account for the wind effect when firing. I know they have a wind-vaine mounted on the turret roof.

Posted by: Thermo

Posted on: 00:40:32 11/06/98

Message: : I noticed this the other night while practicing offline and wondered if it may be a bug. In the picture above, I went full rudder and into a skid. I then fired all my rockets, but the rockets went in the direction of flight rather than direction of the nose. Wouldn't rockets fire in the direction the plane was pointed, like bullets? Or will their fins point them in the direction of travel upon release?

I think the rckts would travel in the direction of the nose at first then would gradually curve to the direction ofthe slipstream.

Think of an FBD on the rckt, you have weight, thrust, lift, and lateral forces all contributing to the direction of motion. The lateral forces due to being launched at some other angle to the slipstream would produce something other than a straight line.

Just one Mechanical Engineer's briefly conceived opinion ;).

P.S. Damage modelling is the one that really gets my interest..

JHL