ECH3610 代做、代写 Python/c++语言程序

日期：2024-07-27 06:24

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Compressible Flow Assignment

MECH3610 Advanced Thermofluids

2024 T2

Read the following before getting started:

This assignment is to be submitted electronically through Turnitin via the 'Compressible Flow

Assignment Submission' link on Moodle before 11:59 PM, Friday 26th July 2024.

This assignment must be completed individually. Signs of collusion in the submitted report

will be treated as plagiarism and such cases will be dealt with by the school office.

This assignment can be either typed or hand-written including the use of digital ink. Regardless

of submission style, all working out and solutions must be clearly legible.

Reference to any table(s), calculator(s) or other resources must be clearly acknowledged and

snip(s) of input(s) and output(s) must be included in the assignment.

This assignment is worth 20% of your overall course grade.

Purpose: This assignment will test your understanding of the compressible flow material covered in

this course. The questions are tailored to test various concepts that you may encounter in the future as

an engineer in high-speed flow applications.

Skills: This assignment will help you practice your knowledge on the following which are essential to

your success as an engineer beyond this course:

Configurations where compressibility effects should be considered.

The design of high-speed systems and the associated parameters.

Nozzle design.

Identifying and accounting for supersonic flow phenomena.

Page 2 of 4

2024 T2 MECH3610 Advanced Thermofluids

Scenario:

Due to the growing success of developments in supersonic flight, an aerospace company you work for

is pioneering the design of a new high-speed rocket. You're tasked with various challenges in designing

and analysing the rocket's propulsion system.

Figure 1. Preliminary rocket design

Part A:

The first stage of the rocket system design is conceptualising a design that fulfils the requirements for

the propulsion system.

a. Marketing would like to present an overview of supersonic flight to an audience with a limited

understanding of aerodynamics. Prepare a brief for non-specialists on why understanding Mach

numbers and flow compressibility is crucial in high-speed aerospace applications by

differentiating between Mach 0.5 and Mach 3 flow characteristics. Limit your response to 300

words and use a diagram or chart in your response. (4 marks)

b. As part of the rocket propulsion system design using hydrogen and oxygen as propellant gases,

certain parameters have been defined by the engineering team:

Combustion chamber temperature: 4000 K

Design mass flow rate: 857.7 kg/s

Throat area of the nozzle: 0.4 m2

Mach number at the throat is sonic (M = 1)

Ratio of specific heats (γ) of the flow gas: 1.2

Molecular weight of the gas: 16 g/mol

(i) First, calculate the initial combustion reservoir pressure using the provided

parameters. (5 marks)

(ii) Your team wants to examine the impact of the throat area over a specified range. For

this, alter the throat area from 0.3 m2 to 0.5 m2 in increments of 0.05 m2 and plot the

reservoir pressures against varying throat areas to visualise the relationship. (9 marks)

Hint: It is suggested to use excel/MATLAB for your calculations.

(iii) From your plot discuss the relationship between the choice of throat area and the

required reservoir pressure. In your discussion, provide reasonings for what would

influence your team’s design decisions on these parameters based on the principles of

nozzle design. Limit your response to 300 words and you may incorporate figures and

equations to enhance your discussion. (4 marks)

Page 3 of 4

2024 T2 MECH3610 Advanced Thermofluid

Part B:

Your team has now shifted to the external geometry of the rocket system for the next design phase.

a. To aid the commercial team, your experimental testing team has designed a similarly shaped

rocket and tests it with the flow conditions shown in figure 2. At the location where the ‘X’ is

shown, the static pressure is measured to be 82.6 kPa. Assume , and are 1.005 kJ/kg.K,

0.287 kJ/kg.K and 1.4, respectively. Considering the compressibility criteria of air, determine

the velocity at ‘X’ and state any assumptions made. Additionally, quantify the percentage error

if the flow is assumed to be incompressible. (6 marks)

Figure 2. flow conditions tested.

b. A junior engineer who has only recently been recruited to the team has identified the surfaces

where they think the flow properties will be different on the external surface of the rocket. They

have labelled these surfaces with letters as per figure 3 below. You have been assigned the

responsibility of reviewing whether they have correctly labelled all the surfaces that will be

exposed to different flow conditions. Answer with either 'Yes' or 'No', documenting a

justification for your review result. (3 marks)

Figure 3. Junior Engineer - labelled geometry with flow conditions.

Page 4 of 4

2024 T2 MECH3610 Advanced Thermofluids

c. Based on your review of the junior engineer’s work in b., you are tasked with using your

knowledge of shock-expansion theory to calculate the Mach number, Prandtl-Meyer function

and pressure for all faces that will be exposed to changing flow conditions as shown in figure

3. To ease your manager's workload, summarise your findings in a table similar to Table 1

shown below. Use = 1.4 in your calculations.

(19 marks)

Table 1. Summarise your solutions in a table like this.

Face/Properties Mach number ()

Prandtl-Meyer

Function ()

Pressure ()