DATA COMPARISON AND RESULTS:

DATA COMPARISON

Results:

   The Mini turbojet engine was successfully designed , fabricated and tested. The engine self sustained at  20 l/min fuel  flow and continued to run for 30 seconds.  The Combustion Chamber wall temperature readings show that the mini turbojet’s flame tube is highly efficient in containing the combustion flame thereby keeping the walls of the combustion chamber at acceptable temperatures. The data comparison shows that the engine has run successfully and well within its limits. The engine could achieve higher performance however  the lack of some instruments for vital parameters and safety reasons prevented us from testing the engine further.

DATA OBTAINED AND GRAPH:

DATA OBTAINED FROM TEST IN WHICH THE ENGINE SELF SUSTAINED 

OVERALL GRAPH 

ENGINE TEST VIDEOS:

ENGINE START:

                   The video shows how the engine is started using the blower .

         

ENGINE TEST: 

           The video shows the final test of the engine where it ran smoothly without glitches and self sustained.              The data obtained  from this test was final  and was used to plot the graphs.

ENGINE LAYOUT AND TEST SETUP

ENGINE LAYOUT

TEST SETUP

The mini turbojet engine was successfully fabricated and the engine and its complete systems were installed and set up for testing as shown in the above image. A standard procedure was followed to start and run the engine 

PROJECT COST:

STARTUP MECHANISM :

The turbojet engine requires external air from a blower initially to start the engine and sustain it till the engine self sustains  .The following hand held air blower was used for starting the engine.

Air Blower  Specifications :

Manufacturer : Pro-Cut

Model : PR-MC28-550

Power Consumption : 550W

Wind Volume : 2.5m3 / min

Max. RPM : 13000

Wind Velocity: 22.4 m/s

Operating Voltage : 220V

INSTRUMENTATION:

In order to study the engine during its functioning there is a need to use some measurement devices to measure important parameters of the engine .This system contains those devices.

ØFuel Flow measurement

ØTemperature measurement

ØPressure measurement

Thermocouple Reading And Switch

Fuel Flow Meter

LAYOUT OF THE THERMOCOUPLE ASSEMBLY:

•K-Type Thermocouple – Chromel & Alumel

•Type K (chromel {90% nickel and 10%    chromium}—alumel {95%       nickel, 2%  manganese, 2% aluminium and 1% silicon}) is the  most common general purpose thermocouple

• It has a sensitivity of  approximately 41 µV/°C

•Range: -20 oC - 1270  oC

The thermocouple was spot welded onto the required points and sealed with high temperature cement.

COMPRESSOR PRESSURE MEASUREMENT:

  The instrument used is an electronic pressure transducer     coupled with a Digital pressure indicator. Its rating is 0-2   bar .

IGNITION SYSTEM:

The Ignition system used in this engine is a spark ignition system .An electronic Spark generation and timing circuit has been used .The ignition system has the following components.

Electronic Spark timer unit:

Spark Plug:

FUEL SYSTEM:

The fuel used for the turbojet engine is LPG . The reason for using gaseous fuel is that it’s storage and delivery mechanisms are less complicated than liquid fuels .

The fuel System has the following components:

  19 KG LPG Cylinder

  High flow rate delivery valve

  Flow meter for measuring flow rate

  Rubber Gas Tubing

  Fuel Inlet fittings & Injector (Brass)

 Fuel Inlet Specifications: 

  Internal Diameter:6.3mm  

  External Diameter:8.2mm 

LPG Cylinder With Flow Meter

High Flow Rate Regulator

Brass Fuel Inlet Fitting

Fuel Inlet 

LPG SPECS

LUBRICATION SYSTEM

Submersible Pump Specs:

Manufacturer : Millborn

Model : AM 1

Shaft Type : Stainless Steel

Suction Mechanism : Side suction

Flow rate : 400 litres/hour

Power Consumption : 20W/220V

Lubrication Oil Specs:

Manufacturer : Shell

Oil Type : 20W40

MATERIALS AND MANUFACTURING

MANUFACTURING :

Material Used:

Mild Steel - (Combustion Chamber Outer, Flame tube ,Flanges, Spark Plug Fittings,   Air inlet manifold, Nozzle)

 

ØMild steel is the most common form of steel as its price is relatively low while it provides material properties that are acceptable for many applications.

ØMild steel has a low carbon content (up to 0.3%) and is therefore neither extremely brittle nor ductile.

Brass - ( Fuel Injector & Fittings)

  Alloy Type: Binary

  Content: Copper & Zinc

  Density: 8.3-8.7 g/cm3

  Melting Point: 900-940 °C

COMPOSITION Of Mild Steel:

  

  Element                       Weight %

  C                                   0.18-0.23

  Mn                                0.30-0.60

  P                                   0.04 (max)

  S                                   0.05 (max)

Properties Of Mild Steel:

  Density:              7,861.093 kg/m³(0.284 lb/in³)

 

  Tensile strength:   500 MPa (72,500 psi) Max

 

  Young's modulus:  210 GPa.

 

  Melting  point:       1350-1530°C (2462-2786°F)

Methodology:

• Mild Steel pipes of Required Diameter were obtained and cut to required specifications.

• The joints were TIG welded .

• The Flanges of the sections are held by Fasteners.

• The fittings for the fuel inlet and spark plug holder were fabricated using manual lathe using the turning process.

• The combustion Chamber is sealed usng a rubber O-Ring.

• The flame tube holes were drilled using a drilling machine.

• The air flow pipe coupler was drilled and then threaded for fitting the pressure transducer.

IN PICTURES:

   FABRICATION:

Combustion Chamber  & Flame Tube:

NOZZLE FABRICATION:

As shown in the picture the nozzle was fabricated and then TIG welded onto the turbo's outlet . However during the the first attempt the weld didn't hold and cracked on cooling . The weld didn't crack during the second attempt .

DESIGN

Combustion Chamber :

Flame Tube:

CC Outer Flange:       CC Inner Flange:

    

Nozzle:

Flat Plate Connecting CC With Turbine:

Connecting Tube: