Engine plate?

[boriz]

Any way I can avoid THIS without an engine plate or cowling ?

 

[Grenartia]

Not with that particular engine and tank diameter. 

[boriz]

Different engine and diameter.

Another different engine and diameter.

[boriz]

Anything "particular" you'd like to add?

[Madeline]

you can use the interstage nodes on fairings  to use them like engine plates or interstages

[boriz]

Sorry. Been drinking.

The question remains...

"interstage nodes on fairings" [sic]

 

Thank you, but no 'cowling' (fairing if you prefer).

[boriz]

Thank you for your answers. But Cowling (fairing) adds weight, as does an engine plate. That's my question.

[Grenartia]

24 minutes ago, boriz said:

Sorry. Been drinking.

The question remains...

"interstage nodes on fairings" [sic]

 

Thank you, but no 'cowling' (fairing if you prefer).

Why are you so deadset on not using engine plates or fairings? Its either use those, or live with the ugliness of mismatched-sized parts. 

Just now, boriz said:

Thank you for your answers. But Cowling (fairing) adds weight, as does an engine plate. That's my question.

Not significant enough weight to actually matter. 

[boriz]

"Not significant enough weight to actually matter.  " - Add half a ton just for aesthetics? Perhaps, but no thanks.

I guess my rockets will look unusual, and there's nothing can be done.

[Grenartia]

Just now, boriz said:

"Not significant enough weight to actually matter.  " - Add half a ton just for aesthetics? Perhaps, but no thanks.

I guess my rockets will look unusual, and there's nothing can be done.

Not just aesthetics. Mismatched sized parts also produce extra drag, IIRC, and fairings and engine plates reduce that. Also, again, its really not that significant weight. If a half ton of drag-reducing aerodynamics is gonna kill your 1.875m design, either your design parameters are too strict, or your design isn't properly optimized. 

[boriz]

Thank you for your input. THIS or half a ton extra useless weight. I choose THIS.

 

[Grenartia]

4 minutes ago, boriz said:

Thank you for your input. THIS or half a ton extra useless weight. I choose THIS.

 

No need to get salty, dude. You wanna throw away drag savings? Fine by me. I was just giving you free advice that you asked for. 

[Hotel26]

I think f12 opens the aerodynamics overlay and this might be the fastest way to bring home the drag penalty for nodes mismatched in size.

Launch your rocket and use f12 to take a look where the significant drag is: maybe in your case it is not so bad.  (Make your own conclusion.)

Then, if you like, put a fairing around it and compare.

In my case, I run KER and I have Acceleration displayed in the HUD.  Probably too much effort to do this, but I'd be looking at it, comparing.

An easier way is to do a couple of launches to orbit with and without a fairing and compare the time it takes to raise AP above 70km.  That's an easy comparison.  It's also the bottom line that will show which is worse for you: a little more weight or (a lot) more drag.

Edited June 22 by Hotel26

[Grenartia]

Also, there is a creative way to arrange certain parts to eliminate the mismatched sizes, but its only going to make your rocket look ridiculous in a Bezos-like way, and will require a longer 1.25m tank on the first stage.

[Hotel26]

P.S.  Whether one version or another takes 30s longer or not to get to orbit, is not really the issue either, I should state.  One is going to burn more fuel getting to space and that may mean less fuel available once in orbit.  That may make or break a desired destination (dV).  And it may necessitate orbital refueling, which now gets into mission controller time & wages (i.e. your time) .

I have payloads that are going to the Kerbin environment only and will operate there indefinitely, periodically refueling; in those cases, I care less about drag/efficiency on the way up.

So, consider this also.

Edited June 22 by Hotel26

[boriz]

Thank you everyone for for your answers. I think I'll go with ugly and lite.

 

Edited June 22 by boriz

[Fizzlebop Smith]

4 hours ago, Grenartia said:

No need to get salty, dude. You wanna throw away drag savings? Fine by me. I was just giving you free advice that you asked for. 

I am curious as to what those drag saving would equate to.

Is there a way to determine if there would be a net gain due to reduced aero drag up to breaking atmo? Not so much time to orbit, but direct fuel cost.

I am not trying to be pedantic on this particular ship.. but more one the larger beasts the end up with an extra 3-5 tons of drag reducing parts.

I think the visual appeal alone is worth justifying the additional weight but I do not shoot for increased realism outside of simple lifesupport.

Now I'm gonna spend my morning launching some rockets.. and doing it again sans fairings.

Edited June 22 by Fizzlebop Smith

[Scarecrow71]

2 hours ago, boriz said:

Thank you everyone for for your answers. I think I'll go with ugly and lite.

I think what you really need to check for when launching said rocket is wobble at the joints above and below the mismatched part sizes.  Although the design you provided above shouldn't have much (if any) wobble, larger craft will almost certainly flex in weird ways right around that spot you don't want to use a plate or fairing at.

[boriz]

Apologies if I came across salty. Once a week I treat myself to some whiskey. Probably the wrong time to post anything.

[modus]

I use this:

 

[DeadJohn]

On 6/23/2024 at 3:10 PM, boriz said:

Apologies if I came across salty. Once a week I treat myself to some whiskey. Probably the wrong time to post anything.

Ah, that explains it. I was wondering why you were ignoring 2 good ways to get what you wanted and kept arguing with people for a 3rd way to do it.

Anyway, you can try offsetting parts. Shift the engine downwards or shift the decoupler upwards. The upper stage engine will be hidden inside the lower stage tank. It will look better cosmetically but might trigger explosions while decoupling.

[boriz]

Another good suggestion, thanks. I do prefer to avoid clipping where able though. Small amounts of clipping can be ok for aesthetics, but fully concealing a part ... ick ... too much like cheating.

I was particularly 'tired and emotional' that night. I was having a little Donald Sutherland movie fest. Watched three movies back to back and 'raised a wee dram'.

(Invasion of the body snatchers, The puppet masters, Virus +  a whole 70cl bottle of Jim Beam. )

[SethM]

Engine plates double as decouplers, just remove the decoupler and put the engine plate above the engine.

[Grenartia]

8 hours ago, boriz said:

Another good suggestion, thanks. I do prefer to avoid clipping where able though. Small amounts of clipping can be ok for aesthetics, but fully concealing a part ... ick ... too much like cheating.

I was particularly 'tired and emotional' that night. I was having a little Donald Sutherland movie fest. Watched three movies back to back and 'raised a wee dram'.

(Invasion of the body snatchers, The puppet masters, Virus +  a whole 70cl bottle of Jim Beam. )

So, you could take one of the adapter tanks and invert it, so it narrows from the heat shield down towards the engine, and just use more 1.25m tanks (potentially even side boosters).