Table of Contents
What is propellant mass ratio?
In aerospace engineering, mass ratio is a measure of the efficiency of a rocket. It describes how much more massive the vehicle is with propellant than without; that is, the ratio of the rocket’s wet mass (vehicle plus contents plus propellant) to its dry mass (vehicle plus contents).
How do you calculate propellant mass fraction?
In the cases of a single stage to orbit (SSTO) vehicle or suborbital vehicle, the mass fraction equals the propellant mass fraction; simply the fuel mass divided by the mass of the full spaceship.
How much thrust does rocket fuel produce?
The SRBs burn for about two minutes and generate about 3.3 million pounds of thrust each at launch (2.65 million pounds average over the burn). The three main engines (which use the fuel in the external tank) burn for about eight minutes, generating 375,000 pounds of thrust each during the burn.
What is inert mass fraction of rocket?
Inert mass is used because while we know the payload mass, we generally have no way of knowing the structural mass. To find the “inert mass fraction”, divide the inert mass by the total mass of the stage. In existing chemical rocket designs, the inert-mass fraction of a given stage tends to be between 0.08 and 0.7.
What is payload mass?
amount of mass that can be transported by the vehicle. deadweight.
Which of the following will decrease the effective propellant fraction?
8. Which of the following will decrease the effective propellant fraction? Explanation: This is because the effective propellant fraction is the ratio of the mass of propellants to the initial mass of the system. If inert mass(mf) increases, then the total initial mass(mo) will also increase as mo = mp + mf.
How do you find the mass flow rate of a rocket?
Remember that mdot is the mass flow rate; it is the amount of exhaust mass per time that comes out of the rocket. Assuming the equivalent velocity remains constant with time, we can integrate the equation to get: I = m * Veq . where m is the total mass of the propellant.
How is the specific enthalpy of a thermal rocket obtained?
The specific enthalpy his obtained by integrating the constant-pressure heat capacity from zero to the desired temperature. The Nuclear Thermal Rocket consists of a high-temperature nuclear reactor with a series of thin channels for the propellant, as shown in Fig. 1.
What is the velocity of the rocket propellant?
The velocity of the rocket propellant scales as vex~ (T/m)1/2, where Tis the propellant temperature and mis its molecular mass. In a chemical hydrogen-oxygen rocket, T~ 6000 °K and m= 18 amu.
How do you find the specific impulse of a rocket?
Assuming the equivalent velocity remains constant with time, we can integrate the equation to get: I = m * Veq where m is the total mass of the propellant. We can divide this equation by the weight of the propellants to define the specific impulse.