Nice unrelated video since there are no GBUs or SBDs being deployed here.
Curious then that I cant find any other ordnance bar the SBD and JDAM being permitted to be used at above supersonic speed out of the F-22 or the F-35 (the 35 also has the B-61 nuke cleared for use at a undisclosed speed but we aren’t dealing with nukes).
No, the reason why the SBD and JDAM are permitted for use at supersonic speeds is because both bombs pitch downwards to clear the aircraft when deployed from any aircraft, supersonic or otherwise. Imagine my shock that the unguided bombs and the very old GBU-15 from your video have issues because they aren’t modern smart weapons.
This is also why the F22 does not have clearance to drop unguided weapons at supersonic speeds.
israel buyed the advanced f15e
btw without rwr and some electronics as i know
the F15EX got this engine or even better correct me if im wrong
and we shall see new bombs or somthin else for this awsome aircraft (F15I) hopefully…
Huh thats weird given that it does apply to the F-22 and F-35 as neither can drop unguided or older guided munitions at supersonic speeds. (bar the B-61)
Seems to matter enough that only SBDs and JDAMs are authorized for supersonic release from the F-22 and F-35.
Okay, Mr-know-it-all, you know what the F-22 and F-35 have in common? Let me go ahead and answer, it’s an internal weapon store.
You yet again failed to read.
When there is an open bay, there is no high pressure zone pulling the bombs up, meaning they have no counteractive force stopping them from leaving the aircraft.
Then there should be no issue for the F-22 or F-35 to drop unguided munitions and older generation guided weapons from their bays, oh wait they cant, only the JDAM and SBD are able of being dropped at supersonic speeds from the aircraft, its almost like they have measures in place that allow them to be dropped at supersonic speeds.
If you want actual video evidence how its the bomb forcing the separation we can just go to the B-61-12 video that the USAF released to see that the bomb works to counteract the positive attitude that the airflow imparts onto the bomb.
Without the autopilot of the B-61-12 taking over and correcting the positive rate, the bomb would have slammed back into the F-35, but due to the bomb correcting it’s attitude, it achieved separation and continued on it’s way.
Preface: I don’t know much about super sonic flight, but i do know a little on just regular air movement.
I think the open bomb bay would create a low pressure zone, think of it kind of like the tail end of a car in rain for visual aid, the ordinance would want to get back into that bay in the same way the rain whirls around the back end of a car instead of separating and flying away. but i might be wrong since its supersonic.
Sorta-sorta-not, at high speed and altitude, the air is thinner, and once it reaches it’s equilibrium point, it will continue to flow, the the air in the bomb bay is static, essentially, the difference is, one is under constant pressure (external mount) and the other isn’t (internal mount) which allows it to be able to be dropped, there is also the fact that it already has vertical velocity from inside the bay which can break through the high pressure zone. It’s hard to explain in words, I could draw it up in a second.
This explains it perfectly, but the swirling air below the high pressure pocket causes the bomb to stick, instead of just falling, in the case of a bomb bay, that zone isn’t there, as there is no surface acting as a wing, nor a wing itself. This means the bomb can freely drop because of no upward pressure, and no surface above it causing that pressure to exist.
The drag you are talking about is a different type:
It’s called wake drag/induced drag, which only works in horizontal notation.
well yes, but that wasn’t what i was talking about though. The air moving from bottom and top of car will want to fill the “void” behind the car and thus “bend” in towards each other. I wasn’t talking about the induced drag. just the creation of a low pressure zone with surrounding higher pressure flowing air (like the bomb bay).
I understood almost everything in your post (you might have misunderstood the intention behind mine).
I’m a little confused about this part:
Because that can’t be true, at least to some extent.
The air moving past the plane will be high pressure, but the “pocket” inside the bay will be low pressure. I don’t think falling for 0.5 seconds adds enough inertia to a bomb for it to matter in this context due to the speed and the amount of very sudden drag that induces coupled with the differential pressure. In the same way a leaf might get stuck twirling around it that low pressure zone behind a car, the bomb would want to do the same.
The only logical way a bomb will clear that barrier would be with guidance counteracting the sudden upwards trajectory.
I’ve not gotten to the courses in my degree that deal with airflow at velocities where Mach is a significant factor (>0.3 Mach), but the aerodynamic force is actually more complicated than that (in fact, that slide is from a NASA website explaining why this representation/theory is wrong). The aerodynamic force is really the resultant of the force due to pressure and the force due to friction:
Assuming that the pilots aren’t just leaving the bomb bays open long enough for the pressure to equalize there would be a high-pressure zone in the bomb bay compared to the outside air, but the much higher velocity of the air outside of the bomb bay would likely overpower the pressure difference in air. As the bomb leaves the bomb bay, it would have an upwards moment (the nose starts moving upwards) as the sloped bottom half of the bomb applies an upward force.
What would fix this is either controlling the fins to that they push the nose down (which might not be possible at supersonic speeds, idk), or shoving the bomb out of the bay so hard and/or at a certain negative angle of attack that would nullify the upward force from the high velocity flow.
The air outside the bay is low pressure relative to the inside of the bay, but it is moving at a much higher velocity (so it imparts more force).
The B-61-12 has this exact issue in it’s supersonic testing, it noses up the moment it comes out of the bay and the fins quickly correct and force it into horizontal flight.
So such corrections are indeed possible for modern guidance kits.
loads aren’t the issue, its aerodynamics that would cause it to “jump” back into the plane, on ww2 era bombs it wouldn’t be as much of an issue as they are less aerodynamic and produce a lot of drag so aircraft like the f3d for example could potennatlly drop above mach 1 (but at that point you don’t have wings.)
You’re absolutely right; in high-speed conditions, it’s the aerodynamic forces, rather than load-bearing alone, that challenge pylon stability during release. At supersonic speeds, complex airflows around the aircraft can create pressure differential that affect how a munition separates. Without proper aerodynamic design, the bomb or pylon could encounter turbulence or uplift that might cause it to “jump” or even risk collision with the aircraft. To mitigate this, pylons like the BRU-61/A for the Small Diameter Bomb (SDB) include aerodynamic design considerations specifically for stable, clean release at high speeds. This helps avoid any backward air flow or oscillation that could disrupt the bombs trajectory as it leaves the pylon.
These designs are extensively tested in wind tunnels and during flight trials to ensure stable separation even in supersonic regimes, which is critical for aircraft like the F-15E when operating at or above Mach 1
Correct, but simply opening the bay disrupts the “laminar” effect of the air over the fuselage, and cause it to enter the bay equalizing the pressure almost instantly, not to mention the slight suction created by the bay doors. Should this not be the case?
