Re: MIT Rocketlab's How to Design Build and Operate Liquid Fueled Rocket Engines

From: Ray Schmitt (rjs41_at_comcast.net)
Date: 11/01/04 

Date: Mon, 1 Nov 2004 08:19:53 -0800

The classic text on liquids is George Sutton's "Rocket Propulsion Elements".
Sutton spent years working at Rocketdyne. The book was written over 40 years
ago, has been continually revised, and now is in its 7th edition.

Also Huzel and Huang's "Modern Engineering for Design of Liquid-Propellant
Rocket Engines (Progress in Astronautics and Aeronautics, Vol 147)" is good.
It's more recent (1992). H & H usually fill in the gaps between equations.

Both are available at Amazon.com but are pricy. Any university science
library will have copies.

Later
Ray Schmitt

"David Findlay" <david@davsoft.com.au> wrote in message
news:418359e0$0$31903$5a62ac22@per-qv1-newsreader-01.iinet.net.au...
> Anyone here used the information from this book? I'm trying to do some
> design based on it, although I've found in a couple of places the
formula's
> make great leaps with no explanation. The main one I'm having problems
with
> is Step 9.
>
> <start quote>
> The chamber length is found from Eq. (21)
>
>
> Vc = (1.1) (Ac Lc)
>
>
> However, we must first determine the chamber area or Ac. We do this by
> assuming that the chamber diameter is five times the nozzle throat
diameter
> or Dc = 5Dt, therefore
>
>
> Dc = 1.2 in. and Ac = 1.13 in2
> Therefore,
>
>
> Lc = Vc/(1.1)(1.13) = 2.67/1.245 = 2.15 in
> <end quote>
>
> Having a chamber volume of 2.67 in^3 and calculating the the chamber
> diameter by Dc = 5Dt, the cross-sectional area of the chamber should be Ac
> = 2 pi r = pi * Dc as far as I can tell. But they introduce a figure 1.13
> in^2 for Ac, with no explanation. On the formula page they provide a
> formula for Ac:
>
> Ac = Dc^2 / 4
>
> This produces a value of 0.35 in^2. Any ideas on what is going on here?
What
> is the correct value? I've been trying to follow their example so I can
> build and validate a spread*** for such calculations, but I'm stuck
here.
> I've also been trying to convert the formulae to metric. Has anyone
already
> converted it?
>
> Secondly, is there a better publication out there to superseed this book?
> This book is aimed at static test articles, do other publications apply
> more to flight articles? Lastly, how well will these values apply to an
> aerospike type of engine, specifically an annular version? Would I be able
> to use the same areas and volumes effectively? Thanks,
>
> David
>
> P.S. Sorry for the cross post, but being a historical book now I think
it's
> relavent to both.

Quantcast