Chapter 10, Turbopumps and Their Gas Supplies Video Solutions, Rocket Propulsion Elements

Problem 1

A rocket propulsion system with two TPs delivers the fuel, namely unsymmetrical dimethylhydrazine (UDMH), at a pump discharge pressure of 555 psia, a suction pressure of 25 psi, a flow of $10.2 \mathrm{lbm} / \mathrm{sec}$, at $3860 \mathrm{rpm}$, and a fuel temperature of $68^{\circ} \mathrm{F}$. Using UDMH properties from Table $7=1$ and Eig $7-1$ and its efficiency from $\underline{\text { Table } 10-2}$, determine the following:
a. The fuel pump power for these nominal conditions.
b. If the fuel flow is reduced to $70 \%$ of nominal, what will be the approximate power level, discharge pressure, and shaft speed? Assume that the oxidizer pump is also reduced by $70 \%$ and also the gas flow to the turbines, but that the gas temperature is unchanged.
c. If the anticipated temperature variation of the propellants is between $40^{\circ} \mathrm{F}$ and $+120^{\circ} \mathrm{F}$, describe qualitatively how this variation will affect the power level, shaft speed, and the discharge pressure of the fuel pump.

Kratika Bhadauria

Numerade Educator

02:21

Problem 2

What are the specific speeds of the four SSME pumps? (Use the data given in Table 10-1.)

Khoobchandra Agrawal

Numerade Educator

14:58

Problem 3

Compute the turbine power output for a gas consisting of $64 \%$ by weight of $\mathrm{H}_{2} \mathrm{O}$ and $36 \%$ by weight of $\mathrm{O}_{2}$, if the turbine inlet is at 30 atm and $658 \mathrm{~K}$ with the outlet at $1.4 \mathrm{~atm}$ and with $1.23 \mathrm{~kg}$ flowing each second. The turbine efficiency is $37 \%$.

Saman Zulfiqar

Numerade Educator

03:07

Problem 4

Compare the pump discharge gauge pressures and the required pump powers for five different pumps using water, gasoline, alcohol, liquid oxygen, and diluted nitric acid. The respective specific gravities are $1.00,0.720,0.810,1.14$, and 1.37. Each pump delivers $100 \mathrm{gal} / \mathrm{min}$, a head of $1000 \mathrm{ft}$, and has arbitrarily a pump efficiency of $84 \%$ Answers: $433,312,350,494$, and $594 \mathrm{psi}$; $30.0,21.6,24.3,34.2$, and $41.1 \mathrm{hp}$.

James Kiss

Numerade Educator

02:33

Problem 5

The following data are given for a liquid propellant rocket engine:
\begin{tabular}{|l|l|}
\hline Thrust & $40,200 \mathrm{lbf}$ \\
\hline Thrust chamber specific impulse & $210.2 \mathrm{sec}$ \\
\hline Fuel & Gasoline (specific gravity $0.74)$ \\
\hline Oxidizer & Red fuming nitric acid (sp. gr. $1.57$ ) \\
\hline Thrust chamber mixture ratio & $3.25$ \\
\hline Turbine efficiency & $58 \%$ \\
\hline Required pump power & $580 \mathrm{hp}$ \\
\hline Power to auxiliaries mounted on turbopump gear case & $50 \mathrm{hp}$ \\
\hline Gas generator mixture ratio & $0.39$ \\
\hline Turbine exhaust pressure & $37 \mathrm{psia}$ \\
\hline Turbine exhaust nozzle area ratio & $1.4$ \\
\hline Enthalpy available for conversion in turbine per unit of gas & $180 \mathrm{Btu} / \mathrm{lbm}$ \\
\hline Specific heat ratio of turbine exhaust gas & $1.3$ \\
\hline
\end{tabular}
Determine the engine system mixture ratio and the system specific impulse.Answer: $3.07$ and $208 \mathrm{sec}$.

Chai Santi

Numerade Educator