Me163 climb - this can't be right

[niklas]

Originally posted by illo
Btw. It seems that red line (enchanged afterwards) takes in account weight loss from fuel consumption.

correct

So with full tank (which never runs empty)  climb to 10km would take 2min 10sec.  (calculations were usually done for full load.)

210 seconds arenīt 2min 10seconds. As long as we go with a non-decimal time system

niklas

[niklas]

Originally posted by LLv34_Snefens
Thanks Illo. cool graphs

I think however the last graph DO take weight loss into account?

Probably.
We can get an average climbrate for a given alitude band easily out of the last graph, because speed is dx/dt.

with dx = 2km

alt. --- t_end --- dt ----- v_climb(2km average)
-0km : 60s
-2km : 97s ------ 37s --- 54m/s  
-4km : 126s ---- 29s --- 69m/s
-6km : 151s ---- 25s --- 80m/s
-8km : 173s ---- 22s --- 91m/s
-10km: 191s --- 18s --- 111m/s
-12km: 208s --- 17s --- 117m/s

It goes along with the red line.

Those data is project data btw, calculated, like most german stuff available in the net.

niklas

[LLv34_Snefens]

Illo, that might be, but I can't believe that such an angle would be very efficient to use. I haven't done any calculations on it, but my intuition tells me (dangerous I know ) that the kinetic energy would be used up long before even getting close to 40K ft. (or even 30), despite the engine running on full power.

Hazed, even our propplanes can go vertical for a while after take-off. The Komet would be even better at this, so maybe it was just a "show-off"?
Off course I am not 100% about the thrust, that was one of the reasons I started this. I found a picture of a museum Komet that clearly shows the exhaustion, where only a single chamber can be seen.
Like the description says it's maybe just a dummy, but even so they would probably make it authentic looking anyway:

http://www.sml.lr.tudelft.nl/~home/rob/me163/berli004.htm
http://www.walter-rockets.i12.com/design/comb.htm
A better view of the combustion chamber. I can see where you get the 4 holes from now. I don't know enough about such engines to know how they calculate thrust, but it seems unlikely that they would give out thrust for each fuel outlet

Nikas. the 2m and 10 sec Illo is refeering to comes from when retracting the 60 secs it uses before starting climb from the 190 secs it uses from start to 10km. that's 130 sec = 2min and 10 sec

[Starbird]

The rocket motor for the 163 had just 1 combustion chamber and exhaust.

Here is a site with info on the motors used.

http://www.walter-rockets.i12.com/walter/me163b.htm

[whgates3]

hey Niklas - you never gave the answer to this

guess the A/C you posted a while back
you stumped us all - will you now divulge the secret ID of the aircraft?

[illo]

Originally posted by niklas


210 seconds arenīt 2min 10seconds. As long as we go with a non-decimal time system

niklas

err thanks

[niklas]

sry i assumed you refer to total time. But after that K4 chart there seem to be some misunderstanding about minutes and total seconds....

whgates, i replied already in the thread that i donīt know the exact designition myself, search for the thread (or my user name) to read it. Probably someone who can understand russish language can ask in russish forums (airwar.ru?) whether they know this aircraft.

niklas

[Masherbrum]

ROCKET powered, not prop, turbojet, ramjet, turbo prop, ROCKET powered.  

How come the Saturn V was launched at a 90degree angle and not 30?

Masher

[LLv34_Snefens]

How come the Saturn V was launched at a 90degree angle and not 30?

Because unlike the Me163, the Saturn V had a Thrust/Weight > 1 (7.5 million pounds of thrust / 6.2 million pounds in weight = 1.21) that ALLOWED it to climb at 90 degree

Just because something is rocket powered does not guarentee a vertical climb.