Tampereen suihkuseurapiiri

Proudly presents :

The Eunuch 1

"Maailman munattomin menopeli"

Fig1: Eunuch 1 with afterburner.

The following pages are again operational.

Eunuch 2 page.

1998 projects page , mukana turboahdettu saunankiuas!

2002 Projects Includes new turbojet project, airliner jet engine and more Eunuch2 pictures.

The Builders

"Tampereen suihkuseurapiiri" consists of four MSc:s which one day got the idea of building a jet engine from an old truck turbocharger.

Fig2: Builders of the jet (in alphabetical order):
Kimmo Ahola, Sami Kiiskilä, Matti Matarainen and Kimmo Pietarinen.

Background

The idea itself is old and so are the first prototypes. We were slowly developing our jets when last month we decided to put our first goal to develop a turbojet driven vehicle for annual drag race that took place on the parking lot of Tampere University of Technology , Finland. The timetable was quite tight but we managed to achieve our goal and "Eunuch 1" was clearly the device that collected most audience at the happening. At the race our vehicle (at that time under the name "Tunturi Reaktioturbo") performed fantastically and got the honourable record of lowest speed. In the future we will continue to improve our vehicle by adding more power to the jet and obtaining a more rigid platform instead of the bicycle.

The Vehicle

The " Eunuch 1 " consists of a turbojet, the auxiliary equipment required for the turbo and a bicycle that works as the platform on which the whole system is assembled on.

Some technical details

Lubrication system

Oil circulation for the jet is achieved by pumping oil through it by an old car oli pump. The pump is installed in a rectangular metal box that acts as an oil tank. It is being driven by a DC motor from an old cleaning machine and powered by a 12V motorcycle battery. One of the switches in the control box turns on the pump and the other starts charging the battery if the vehicle is plugged into an external power unit. The oil pressure can be checked from a meter behind the vehicle. The rectangular device left from the meter is a pressure switch that automatically shuts down the fuel pump if the oil pressure drops below 1 bar and the cylinderical device right from the meter is the oil filter.

Injection nozzle and fuel pumps

We use ordinary diesel fuel to power the jet. The fuel is injected in the combustion chamber through a nozzle that has been found from the remains of a dismantled russian jet bomber. The fuel is pumped in the nozzle by a pump that originally has been in an oil burner for ordinary household central heating system. The fuel injection pressure controls the power output of the jet and it can be varied by changing the speed of the fuel pump. A DC motor drives the fuel pump and it's speed can be adjusted by changing it's input voltage between 0 and 50 volts by a chopper based voltage controller . The power source for the pump is a package of NiCd batteries that are installed inside the controller box. It can be charged with the same external power unit than the battery for the oil pump. The afterburner has similar DC motor but only with an on/off switch. The pump is also a bit different but it uses the same battery pack as the main fuel pump. These DC motors are not from an old cleaning machine but from a disassembled computer printer. There are two potentiometers in the voltage controller unit. One of them is used to adjust the jet to a minimum power that keeps it running. The other is installed near the driver's hand so that he can turn the jet to full power by just a move of his finger.

Ignition

The third battery in the system drives the igniter unit . It has an ordinary car ignition transformer driven by a samiconductor switch and an oscillator. The device generates high voltage pulses that produce sparks in a car spark plug that is been inserted in the combustion chamber. After the jet starts the igniter unit may be switched off.

The old bicycle turn out to be far too weak to withstand the weight of the jet, driver and auxiliary systems so we had to weld some metal pipes to keep it together. The weight of the jet makes the vehicle quite unstable so we also added two wheels to prevent it from falling if something goes wrong.

Startup sequence

The startup of the jet is done by first starting the airstarter unit , which is made of an old leaf blower. Second phase is to switch on the oil pump and third phase is to switch on the igniter unit and fuel pump while the air from the airstarter is directed in the jet inlet. After the ignition has occurred and the jet RPM is high enough the airstarter hose can be removed and the igniter switched off. Now the vehicle is ready for use , the driver can adjust the thrust by just turning the fuel pump potentiometer. In the need for extra power the afterburner can be started just by pressing a button near the main power potentiometer.

Performance measurements

We have measured 120 N of thrust with a combustion chamber pressure of 1.2 bar and fuel injection pressure of 15 bar. Better joint between the compressor outlet and combustion chamber together with minor adjustments in the flameholder raised the combustion chamber pressure to 2 bar. Thrust of this configuration has not been mesured yet, but it's been estimated to be about 200 N. The maximum speed is approximated to be 80 km/h but since the bicycle is too weak it is impossible to drive faster than 32 km/h. The afterburner doesn't work properly yet. If the jet is at minimum power the afterburner flame burns completely outside the flame tube. When more power is put in the jet the flame gets extinguished by too fast flow of air. Our first improvement to "Eunuch 1" will be a different flametube and afterburner flameholder which should get the afterburner work properly also at full power.

Our older turbojet projects

We did some experiments earlier with a bigger turbojet. It was much heavier and produced only as much thrust as the smaller one used in the bike so we haven't done much experiments with it since that.
Here are some pictures of the jet from the inlet side and from the output side. We used at this construction the leaf blower to run the fuel and oil pumps. The power was well enough for the pumps when the blower engine was at mimimum throttle and only at startup when we needed to put it on full throttle. The system did work but it was quite big and heavy and worst of all the sound of the leaf blower masked off some of the cool sounds of the turbojet :) So we decided to use the lighter, more silent and easilly controllable electric motors for "Eunuch 1".

The startup was a bit more complicated as with "Eunuch 1". The positioning for the ignition plug was improved in it's engine but in this old unit we had to drill a small hole in the combustion chamber. Through it we could inject gasoline in the chamber with a syringe at startup. The gasoline then ignited and the main fuel started to burn too. The jet usually blew out a flame at startup and then started to run smoothly. Sometimes the turbine wheel did glow mildly when the jet was at full power. When a flameout occurred the jet produced a dense cloud of smoke that consisted of vaporized diesel fuel. Here are the key components of the jet: turbocharger, combustion chamber and flameholder. We tried to increase thrust also by adding an output nozzle and afterburner flametube.. The afterburner did worked but there weren't enough increase of thrust so we tried to try a lighter jet with same power.

Here is the engine of "Eunuch 1" assembled on a testbench. The system is placed on a slide bars and there is a torque meter connected between the jet assembly and a steel bar that is hammered in the ground. With this system we managed to measure the 120 N thrust from the jet.

Eunuch 2

The "Eunuch 2" uses the same engine as the "Eunuch 1" but vehicle platform has been changed from a bicycle to a moped. This change has greatly increased the ability to drive the vehicle and we are hoping to achieve better speeds than with "Eunuch 1". We did some minor modifications to the jet's auxiliary equipment too. The oil pump system has had most changes. We have now a heavy oil burner pump connected axially to an electric motor that runs on 50V. This has eliminated the need for the big and heavy motorcycle battery since this motor can use same NiCd batteries as the fuel pumps. The oil tank has also been reduced in size and the main fuel pump assembly has a more rigid construction similar to the new oil pump assembly. The oil pump motor is the black cylinder on lower right side and the main fuel pump is on the lower left side of the bike. The batteries are on both sides of the seat and the new electric control unit is on the front. The electronic control unit is now more advanced. It can control the speed of the afterburner fuel pump proportionally to the speed of the main fuel pump. This allowed us to run the afterburner properly several times. The thunderlike sound and the white-blue flame that showed from the end of the flametube were quite promising.

We had to put a long conical shaped output nozzle to the jet so that the hot gasflow can be run under the driver's seat. Unfortunately this nozzlepipe is not visible since we put another steel pipe over it. This shield pipe is bigger than the nozzlepipe and a bit longer too. The idea of having it longer is to cause venturi effect to pull air through the gap between the nozzlepipe and the shield pipe. This air cooling did work and the driver's seat didn't melted even with the jet at full power. The jet is barely visible since we also put sheets of aluminium around it to prevent the driver to touch the hot turbine casing. We demonstrated this bike on an annual event "Kowan teknolokian päiwät" where antique engines, steam engines and antique agriculturar machines are operated for the audience. The show was run on and old field and therefore we couldn't ride on the bike. Asphalt paving is definitely required because the rocks that bounce from the ground could otherwise get into the compressor and break the compressor wheel. We did some test runs on the jet and especially the smoke puffs from afterburner tests collected collected a good audience.