# Aerospace Ramjet Rocket engine hybrid?

1. Aug 31, 2010

### TERR0RBYTE

I wanted to get some opinions on this, I am serious considering designing a ramjet rocket hybrid engine for my 3rd year mechanical engineering degree project and have started doing the research to see exactly how much work it entails I still can't quite decide... is this a realistic project? (my heart says yeh! but my mind says I am biting of more than I can chew to do it in much detail which is needed for a good grade). Any advice?

2. Aug 31, 2010

### john.phillip

Is probably better for you to try to discuss this subject with your professor and findout what he thinks. You can make any design as hard as you want, no matter how simple it might look, but whether you are going to satisfy the demands and requirements of your professor is another story.

3. Aug 31, 2010

### mugaliens

Sounds like a fun, but definately expansive project. In addition to checking with your instructor, consider reviewing previous papers, probably either at your library, or possibly within the department, as a way to get a better feel for the typical nature and scope of projects.

4. Dec 29, 2010

### TERR0RBYTE

Yeh i went ahead and did it now, and really wish i had not but its a great learning experiance though a very steep learning curve with alot of work even though i am trying to keep it as simple as possible.

I have one question, i never took chemistry (and for some reason we missed the thermodynamics section at my uni, shocking i know, had to learn it myself) I am trying to find out a very approximate pressure in my rocket combustion chamber given that I am using a O2 H2 mix for propellent/oxidizer combo. I have been trying to find the equations to use, would this one work for a rought estimate (I found it in a old book V was not defined but I assume volume):

P = (C/V) (R T/M)

Where:
P is max pressure, C is mass of propellent, V is volume (or rather my combustion chamber area I assume) R is universal gas constant, T is max temperature, M is average molecular weight.

or could i just use P = nRT/V where n is moles in this case? In equations like this is volume just the area that the gas can expand to, or for my purposes the combustion chamber).