3rd year final presentation mechanical engineering
TRANSCRIPT
To Create a Combustion Chamber for a Prototype Jet
EngineEoin Robinson
Design Specification
To create combustion chamber and a housing for a jet engine prototype.
Has a capacity to operate and withstand temperature of approximately 540- 630°C.
Combine with Turbine section and fuel supply sections.
Design and operation
Images acquired from Jet engine prototype book and www.designtechnology.org
Operation
The operation of a jet engine combustion chamber is similar to that of a four stroke cylinder combustion chamber.
Image acquired from www.salvatoreaiello.com
Combustion chamber components
Components
Front sectionFront part (9.2)Hooked tubes (x 6 ) (9.3)Air jets ( x 6) (9.4)Jacket (Middle section)Sleeve (8.1)Rear (8.2)Outlet (8.3)Housing (outer section)The housing jacket (17.1)Pressure nipples (18)Fuel pipe (17.1)
Index courtesy of the Jet engine book
Finished Design * Note : All components shown in this drawing were made on Creo/Pro-E . Air compressor not part of this project.
Fuel intake
For combustion to be successful:The chamber will have to accommodate
Kerosene fuel being burned at temperatures reaching from 540- 630°C.
Must be raised to a pressure of 1 – 3 bar .Outer casing must have apertures for the
manometer, kerosene tube and propane tube (for ignition).
Must maintain an air to fuel ratio of at least 1:10.
The Flame tube
The purpose of the flame tube is to regulate the amount of air being fed into the combustion chamber.
The holes provide gradual increase of air into the combustion jacket.
It is very important that the air speed is not too fast because if it is the flame will be snuffed out or the fuel will simply be blown away.
Primary, secondary and Tertiary zones
Primary Zone: the area in which the fuel igniters come into contact with the air.
Secondary Zone + Tertiary : larger diameter holes which provides remaining colder air to mix with.
Completed assembley
Primary zone Secondary zone
Tertiary zone
Materials Needs
Issues with materials & manufacture
Welding equipment not designed to work with stainless steel. (Highly specialized)
Lack of filler materials Cutting equipment not designed for
complex shapes.(Bandsaw)Bending Austenitic steel very difficult E =
190 Gpa.FAS facility unworkable
Materials Analysis
Austenitic stainless steel 304/314
There are many factors contributing to the selection of austenitic stainless steels. The main factors were:
Easy to acquire / ubiquitous ( with the exception of 321) Can operate at high temperatures ( AISI 304, 316, 316L, 321
can all withstand the anticipated operating temperature of 650°C)
Can be welded Not magnetic Relatively cheap (AISI 304, 316, 316L could each be acquired
for less than 100€ for 1000mm x1000 x .5mm sheet Highly ductile Strength and Hardness can be increased by Cold working. Solution Annealing increases tensile strength
Bill of materials
Stainless Steel families
Austenitic Ferritic Duplex Martensitic Precipitation hardening
Source: Azom.com
Methods of Manufacture
Brazing Annealing Bending (for the sheet Steel)DrillingCutting
Shift Focus
Deficiencies in manufacturing equipment and expertise on my part meant this project could not be constructed form AISI 304/314.
Alternative manufacturing equipment SLS/RPD Machine .
SLS /RPD Machine
The SLS machined takes a design rendered on CAD and builds it slowly by layers and layers of polymer dust.
Model
Tasks completed
Pro-E Drawings Requisition sheets Polymer model of the Combustion
chamber and outer casing prototypeFinal Report
Thank you !Any questions