Liquid rocket engine excercise

[mirko9670]

Homework Statement

Find thrust and specific impulse

Relevant Equations

How can i derive the thrust? i am missing some parameters

I know it is an homework excercise but I already tried all the isoentropic relations, the problem is not the Isp, I can't find a relation to calculate the thrust as I am missing some important parameters, such as Ae, At, mdot, and thrust. This is the text of the excercise:

A bipropellant rocket engine is required for Mars landing. It will be the main engine driving the soft landing of a capsule on the martian soil to carry a scientific payload. The ground environment where the lander will operate is characterized by the following properties: Temperature: -60°C Pressure: 610 Pa Composition: mainly CO2 Acceleration due to gravity force: 3.7 m/s2

Show the formula and compute the thrust and the specific impulse for this propulsion unit if the following properties are obtained. (Assume isentropic expansion) Chamber pressure: Pc = 15 bar Exit-to-chamber nozzle pressure ratio: OPTIMAL EXPANSION Nozzle exit velocity: Ve = 2450 m/s Specific heat ratio: 1.3 Molar mass of exhaust gases: 24 g/mol

 

[sbrothy]

I’m aware this is an old post but it’s still unanswered so, I’m providing this, admittedly, vague answer to the best of my abilities.

I’m assuming you mean a Nuclear Thermal Rocket.

The Atomic Rockets website on NTRs, although probably neither scientifically accurate nor rigorous, often provide links to more serious papers in the text when the host admits he’s out of his depth.

Perhaps something of value can be gleamed. I know there are lots of generic tables and nomograms.