Question: A Small Solid-fuel Rocket Motor Is Fired On A Test Stand. The Combustion Chamber Is Circular, With 130 Mm Diameter. Fuel, Of Density 1530 Kg/m3, Burns Uniformly At The Rate Of 14.5 Mm/s. Measurements Show That The Exhaust Gases Leave The Rocket At Ambient Pressure, At A Speed Of 2400 M/s. The Absolute Pressure And Temperature In The Combustion Chamber …

engineeringmechanical engineeringmechanical engineering questions and answersA Small Solid-fuel Rocket Motor Is Fired On A Test Stand. The Combustion Chamber Is Circular, …Question: A Small Solid-fuel Rocket Motor Is Fired On A Test Stand. The Combustion Chamber Is Circular, With 130 Mm Diameter. Fuel, Of Density 1530 Kg/m3, Burns Uniformly At The Rate Of 14.5 Mm/s. Measurements Show That The Exhaust Gases Leave The Rocket At Ambient Pressure, At A Speed Of 2400 M/s. The Absolute Pressure And Temperature In The Combustion Chamber ….A small solid-fuel rocket motor is fired on a test
stand. The combustion chamber is circular, with 130 mm diameter.
Fuel, of density 1530 kg/m3, burns uniformly at the rate of 14.5
mm/s. Measurements show that the exhaust gases leave the rocket at
ambient pressure, at a speed of 2400 m/s. The absolute pressure and
temperature in the combustion chamber are 8.5 MPa and 3600 K,
respectively. Treat the combustion products as an ideal gas with
molecular mass of 25.5. Evaluate the rate of change of mass and of
linear momentum within the rocket motor. Express the rate of change
of linear momentum within the motor as a percentage of the motor
thrust.
A schematic and control volume for the rocket are
shown below.

1. For this control volume, the appropriate
assumptions are (check below)

2. Which of the following basic equations are appropriate to solve
this problem (check below)
a) Incompressible flow

b) Bernoulli’s equation

c) Conservation of momentum in the horizontal x-direction

d) No net pressure force

e) Conservation of momentum in the vertical y- direction

f) Conservation of energy

g) Steady flow

h) Frictionless flow

i) All properties uniform except at the combustion front

j) Conservation of mass

k) Steady state
3.This control volume is divided into three regions
(0-a, a-b, and b-c) as shown. The locations 0, a, and c are
constant with time and b moves to the right with velocity $vb mm/s.
Conservation of mass will be applied to each of these
regions.

(a) For the region 0-a, what is the change in mass with respect to
time?

(b) For the region a-b, in terms of the cross sectional area A, gas
density ρg, and the dimensions a and b, what is the change in mass
with respect to time?

(c) Since the location a is constant with time, what does the
expression in 2 reduce to?

(d) What is the derivative of b with respect to time equal to in
terms of the parameters of the problem?

(e) What does expression in 3 reduce to in terms of the velocity of
the combustion front?
4.

(a) For the region b-c, in terms of the cross sectional area A and
solid fuel density ρf, what is the change in mass with respect to
time?

(b) Since the location c is constant with time, what does the
expression in 1 reduce to?

(c) In terms of the velocity Vb, what does the expression in 3
reduce to?
5.What is the expression for conservation of mass for
the control volume? This will give the flow rate out of the control
volume.
6.

(a) What is the density of the gas in the control volume?

(b) What is the mass flow rate out of the control volume?
7.

The following relate to the linear momentum equation in the
horizontal direction. Terms are positive in the positive x
direction.

(a) What is the force, including the sign, acting on the control
volume?

(b) Including the sign, what is the momentum flow out of the
control volume?
8.

The following relate to the linear momentum equation in the
horizontal direction. Terms are positive in the positive x
direction.

(a) What is the momentum of the gas at crossing the control surface
at location c in terms of the mass flow rate and the gas velocity
Vg, with the sign positive in the positive x direction ?

(b) The momentum of the gas crossing the control surface at
location c is produced by the change in momentum of the solid fuel
in the rocket. Including the sign, what is the change in momentum
of the solid fuel in the rocket? (c) What is the conservation of
momentum in terms of the force Fsx, momentum flow out of the
control volume, and change of momentum inside the control
volume?
9.

The following relate to the linear momentum equation in the
horizontal direction. Terms are positive in the positive x
direction.

(a) Including the sign, what is the magnitude of the force that
holds the rocket in place?

(b) What is the change in linear momentum inside the rocket as a
percent of the thrust?
Show transcribed image Order any type of Service We Provide We are the best assignment service that can satisfy student’s demands in different scientific fields. We perform tasks of any kind. Our specialists provide diverse custom assignment writing services to students from all over the world every day. You can contact us for assistance with: • Essays of any type (application, scholarship, argumentative, personal, informative, persuasive, compare and contrast, narrative, analytical, cause and effect, critical, process, descriptive, expository essays); • Homework, • Assignments, • Reviews of all types (for a book, an article, or a film), • Reports, • Annotated bibliography, • Projects, • Thesis, • Term papers, • Presentations, • Lab works, • Research papers, • Speeches, • Critical thinking, • Capstone projects; • plan; • Coursework’s; • Dissertations. The list is far from complete! Representatives of our student assignment service are connoisseurs of the peculiarities of presentation in regards to academics. Your college a