Turbo Charger Jet engine

Abstract

In this project we fabricated a jet engine by modifying aturbocharger. We used the compressor and the turbine assembly and installed a combustion chamber in between these two, resulting in the production of thrust. Due to revolution of more than 1,00,000. We measured the Pressure created by the compressor with pressure gauge. The Turbocharger approached its limits because of the intense temperature of the exhaust gas.

Introduction

The turbojet is the oldest kind of general-purpose air breathing jet engine.Until 1930’s only reciprocating engines were used, but the rpm of those engines could not exceed 10,000 rpm. So, engineers thought to devise another system which could provide higher rpm’s up to 1, 00,000 rpm’s. As a result of which turbo jet engines were produced.

Basically turbo jet engine consists of three parts (i) air compressor (ii) combustor (iii) turbine. We had a turbocharger which fulfills the requirements of both air compressor and turbine. So, we fabricated a combustion chamber to engineer this turbo jet engine. Turbojets consist of an air inlet, an air compressor, a combustion chamber, a gas turbine (that drives the air compressor) and a nozzle. The air is compressed into the chamber, heated and expanded by the fuel combustion and then allowed to expand out through the turbine into the nozzle where it is accelerated to high speed to provide propulsion. A turbojet engine is used primarily to propel aircraft, but has been used for other vehicles, such as cars. Air is drawn into the rotating compressor via the intake and is compressed to a higher pressure before entering the combustion chamber. Fuel is mixed with the compressed air and ignited by a flame in the eddy of a flame holder. This combustion process significantly raises the temperature of the gas. Hot combustion products leaving the combustor expand through the turbine where power is extracted to drive the compressor. Although this expansion process reduces the turbine exit gas temperature and pressure, both parameters are usually still well above ambient conditions. The gas stream exiting the turbine expands to ambient pressure via the propelling nozzle, producing a high velocity jet in the exhaust plume. If the momentum of the exhaust stream exceeds the momentum of the intake stream, the impulse is positive, thus, there is a net forward thrust upon the engine.

Design

The basic design has four major components:

(i)  Turbocharger

(ii) Combustion chamber

(iii) Ignition system

(iv) Cooling system

Turbocharger:

The turbocharger has three main components:

1.     The turbine, which is almost always a radial inflow turbine

2.     The center housing/hub rotating assembly

3.     The Compressor

 

Working principle:

Turbochargers are a type of forced induction system. They compress the air flowing into the engine. The advantage of compressing the air is that it lets the engine squeeze more air into a cylinder, and more air means that more fuel can be added. Therefore, you get more power from each explosion in each cylinder. A turbocharged engine produces more power overall than the same engine without the charging. This can significantly improve the power-to-weight ratio for the engine.

In order to achieve this boost, the turbocharger uses the exhaust flow from the engine to spin a turbine, which in turn spins an air pump. The turbine in the turbocharger spins at speeds of up to 150,000 rotations per minute (rpm) -- that's about 30 times faster than most car engines can go. And since it is hooked up to the exhaust, the temperatures in the turbine are also very high.

Turbocharger Design& Working:

The turbocharger is bolted to the exhaust manifold of the engine. The exhaust from the cylinders spins the turbine, which works like a gas turbine engine. The turbine is connected by a shaft to the compressor, which is located between the air filter and the intake manifold. The compressor pressurizes the air going into the pistons.

The exhaust from the cylinders passes through the turbine blades, causing the turbine to spin. The more exhaust that goes through the blades, the faster they spin. On the other end of the shaft that the turbine is attached to, the compressor pumps air into the cylinders. The compressor is a type of centrifugal pump -- it draws air in at the center of its blades and flings it outward as it spins.

Bearings:

In order to handle speeds of up to 150,000 rpm, the turbine shaft has to be supported very carefully. Most bearings would explode at speeds like this, so most turbochargers use a fluid bearing. This type of bearing supports the shaft on a thin layer of oil that is constantly pumped around the shaft.

Bearings serve two purposes

(i)     These cools the shaft and some of the other turbocharger parts

(ii)   These allow the shaft to spin without much friction.

                                                                                             

Specifications

1-      This turbocharger belongs to Toyota Hiace 2.3 L.

2-      It has an inducer dia of 1.75 inches.

3-      It was bought from bilal gang Lahore.

(ii)Combustion chamber:

Combustion chamber has two major parts:

1-      Combustion shell

2-      Flame tube

 

Combustion Shell

Combustion shell is the outer shell ofcombustion chamber whichcontains the flame tube. It’s one end is connected to the compressor and other is connected to the turbine.
Spark plug is also mounted on its surface.

Specifications and construction

1-      Combustion shell is made of steel SS(stainless steel) grade 304 and argon welding is used for fabrication.

2-      External dia = 3.87 inches.

3-      Thickness = 1.8 mm

4-      External dia of inlet = 1.51 inches.

5-      Thickness of inlet = 2.05 mm.

Flame tube

It is the inner part of combustion chamber, contained within the combustion shell. Fuel reservoir is connected to it. Fuel jet is thrown with the help of a nozzle in the flame tube. It contains holes for mixing of air with fuel after which a spark is produced with the help of spark plug to combust the air fuel mixture which produces hot gases to run the turbine.

There are three types ofholes present on the surface of flame tube.

1-      Primary holes

2-      Secondary holes

3-      Tertiary holes

Specifications and construction

1-      Flame tube is made of steel SS grade 304 and argon welding is used during fabrication.

2-      Length of flame tube = 10.5 inches.

3-      External dia of flame tube= 2.68 inches.

4-      Thickness of flame tube = 1.8 mm.

5-      Length of fuel jet = 5 inches.

6-      There are 22 primary holes having dia 0.25 inches each.

7-      15 secondary holes having dia 0.5 inches each.

8-      5 tertiary holes having dia 0.75 inches each.

(iii)Ignition system

Ignition system is used to initiate the combustion in the turbocharger jet turbine engine. It has three major components:

1-      Nozzle used to throw a high velocity fuel jet in the flame tube.it has a length of 2.5 inches.

2-       Electronic circuit which provides the voltage of 10kv to the spark plug with an input of 220 volts. This electronic circuit was bought from hall road.

3-      Spark plug used to ignite the fuel. This spark plug belongs to a Honda CD 70cc.

(iv)Cooling system

There are basically two cooling systems used in this engine.

1-      Water cooling system which consists of a power head water pump having a capacity of 600 L/H normally used in aquarium.

2-      Oil cooling system consisting of a viper pump of Honda Civic Reborn.

We used two reservoirs, one for water and one for oil.

 (v) Control panel

Control panel consisting of 3 switches, one for ignition, one for oil pump and one for water pump. There is also a push button for ignition and a voltmeter.

There is also a pressure gage for measuring the pressure of compressor up to 1 bar.

First test run

We used a blower as a starter to give turbine the initial rpm. We released the gas and pushed the ignition button but it didn’t work. So we used a lighter in front of exhaust to manually ignite the air fuel mixture. Our engine started gradually making the turbine red hot by the extreme temperature of exhaust gases. The pressure gage was showing 0.8 bar (11 psi) pressure. We were continuously measuring the temperature of the turbine by using an infrared thermometer. Here is the graph showing the relation between temperature and time.

Conclusion

1-      Our project was an overall success producing a thrust.

2-      The jet engine can be used to power go carts.

3-      The engine shaft was rotating at a destructive RPM of more than 80,000 RPM.

4-      Oil pressure was not sufficient due to which squeaking noises were generated in the engine.

5-      The Fuel consumption of the Turbojet is far more than the convectional reciprocating engine. but the output power limit was much more as compared to it

6-      By adding an Afterburner (future plan) we can momentarily increase the output of the engine by sacrificing more fuel.

Drafting (vehicle)

Drafting is a technique of reducing the drag co-efficient of your motor vehicle by travelling after  the lead vehicle slip stream, the biggest  advantages of drafting is the fuel consumption, which is considerably reduced , I have experimented drafting on highways and I was surprised by the results of the drafting, I sync with a big truck traveling at 60 km/h with a distance of just 5 feet from its bumper, after sync with it I immediately deviated to the other track, keeping the throttle same, and my speed was reduced to 45 km/h which means 25% decrease in speed however there are some tips and tricks for the drafting:

   Always draft with the vehicle of size comparable  to you vehicle size

Keep an adequate distance.

Make sure that the lead vehicle brake lamp is functioning correctly

Never draft in rainy weather. Because the friction of road and tire in reduced thus needs a larger distance to slow down a vehicle.

If the lead vehicle is big as compared to yours, then you can easily keep a large distance.

   If you are on a bike, the best is draft along with a truck. Because in winter season you can avoid the cold breeze easily J

Portable cell charger circuit

If you got a cell phone which you loves, but it don't have enough battery time then this circuit is for you, unfortunately in some 3rd world countries where there is large load shedding this circuit is a must. For making this circuit you dont have to be a circuit genie, its really simple :)

Here is the list of thing you need :

Solder iron (of course :p )
breadboard or vero borad
female nokia or micro usb pin
two way double toggle switch
2x 3.7V betteries (Li-ion)
100uF electrolytic capacitor
330uF electroltyic capacitor
LM2575 regulator IC
1N5819 zener diode
330uH inductor

Now lets get to the point, Here is the circuit diagram,

It uses two li-ion battery, the input is from the cell phone charger pin, the switch is used to toggle between series and parallel connection of batteries, for charging the batteries must be connected in parallel mode, for the operation of the regulator they must be connected in series so that their voltage add up to provide the adequate input for the regulator, the regulator is a switching type regulator which is very power efficient and dont need a heat sink unless you are using it for charging mutilple cell at the same time.