Design Fabrication and Analysis of Air Engine Test Bed
"Necessity is the mother of inventions", We know that the use of the fossil fuel within few years has been exceeded vigorously and the main consumption of these fuel are our Engines, so we brought a solution that is more reliable and more compatible than conventional engines, An Ai
2025-06-28 16:26:26 - Adil Khan
Design Fabrication and Analysis of Air Engine Test Bed
Project Area of Specialization Mechanical EngineeringProject Summary"Necessity is the mother of inventions", We know that the use of the fossil fuel within few years has been exceeded vigorously and the main consumption of these fuel are our Engines, so we brought a solution that is more reliable and more compatible than conventional engines,
An Air engine is basically fueled by compressed air present in the compressor. It is a pneumatic actuator that creates useful work by expanding compressed air. They have existed in many forms over the past two centuries, ranging in size from handheld turbines up to several hundred Horsepowers. Some types rely on pistons and cylinders, others use turbines. Many compressed air engines improve their performance by heating the incoming air, or the engine itself. Some took this a stage further and burned fuel in the cylinder or turbine, forming a type of internal combustion engine.
Project ObjectivesTo develop the analytical model of the inlet and exhaust valve by generating a laminar flow of the fluid to maximize the inlet air pressure.
The force on the piston is directly proportional to the applied pressure, the force reduces when the inlet pressure decreases and increases as the pressure increases. Using the conventional valve causes the turbulent flow of the air that not only decreases the pressure also decreases the efficiency of the engine.
To solve the problem we have proposed a new design of the valve that will move horizontally in and out of the cylinder head. The design is such that the flow will be laminar due to which pressure will not be decreased by the valve to run the engine at maximum rpm.
Project Implementation MethodAfter completion of all CAD drawings and construction, the we were able to see the fruits of their labor. The engines were tested using air from a compressor reduced to approximately 10 pounds per square inch. This was kept as the standard for all teams in order to ensure comparable test conditions. Multiple tests were required to get many of the engines working smoothly as the we were forced to realize the necessity of precision in manufacturing and assembling parts. Some of the engines experienced interferences due to the connecting rods contacting the cylinder wall, and we have to hand finish some of the components to eliminate the problems resulting from lack of precision in their initial fabrication efforts. As a tool for measuring each team’s success, a tachometer was used to determine the speed in revolutions per minute (rpm) of each engine. All of the teams then decided they wanted to spend more time smoothing the surfaces, aligning the connecting rods, making sure the clearances and fits were just right, lubricating the parts and stopping all sources of air leaks. Without even realizing what they were doing, the we were learning the importance of tribology, limits, fits, testing, operation and implementation of the design. All of these aspects help to prepare us for future design-build projects they will experience in the Mechanisms, Machine Design and Mechanical Engineering Design courses during their junior and senior years. The fourteen engines had speeds ranging from 500 to 1800 rpm with an average speed of approximately 1180 rpm and a standard deviation of 180 rpm.
Benefits of the ProjectAir Powered Engine is an alternative technology which uses compressed air to run the engine and thus eliminates the use of fossil fuels. Exhaust temperature of it will be slightly less than atmospheric temperature and thus helps in controlling global warming and reducing temperature rise caused due to other means. As we are going to convert the already existing conventional engine into an air powered one, this new technology is easy to adapt. Another benefit is that it uses air as fuel which is available abundantly in atmosphere. Apart from above other technical and economic benefits are as follows:
Technical benefits:
- The temperature of the engine while working will be slightly less than the ambient temperature.
- Smooth working of the engine due to very less wear and tear of the components.
- There is no possibility of knocking.
- No need of cooling systems and spark plugs or complex fuel injection systems.
Economical Benefits
- No use of expensive fossil fuels as the free air is compressed and taken to use.
- For this reason people can easily shift to the new technology.
- Compressors use electricity for generating compressed air which is relatively much cheaper and widespread.
- Smooth working will lead to less wear & tear, so lesser maintenance cost.
Initial torque is supplied from the DC exciter motor, and then the engine operation starts.
Stage 1: When the piston is in the TDC, compressed air is injected through the pulsed air firing valve, which pushes the piston to BDC.
Stage 2: Due to the motion of the engine and its inertia, the piston moves back to TDC, pushing the air out of the valve. The plunger of the pulsed firing valve is controlled by a timing circuit which is specifically a PLC programmed circuit. It supplies the electronic signals by which the plunger moves so that it opens and closes the pulsed firing valve.
On comparing it with the working of normal SI 4 stroke engine, we can say that:
- “Stage 1” of the air engine comprises of the combined operation of “Suction stage” and “Power stage” of the normal 4 stroke SI engine.
- “Stage 2” of the air engine comprises of the combined operation of the “Compression stage” and “Exhaust stage” of the normal 4 stroke SI engine.
In comparison to petrol or diesel powered vehicles “air powered vehicles” have following advantages:
- Air, on its own, is non-flammable, abundant, economical, transportable, storable and, most importantly, nonpolluting.
- Compressed air technology reduces the cost of vehicle production by about 20%, because there is no need to build a cooling system, fuel tank, spark plugs or silencers.
- High torque for minimum volume. The mechanical design of the engine is simple and robust.
- Low manufacture and maintenance costs as well as easy maintenance. Lighter vehicles would mean less abuse on roads, thus, resulting in longer lasting roads.
- The price of fueling air powered vehicles will be significantly cheaper than current fuels. When the air is being compressed at reasonable speeds, it heats up. The heat given off during compression could be reclaimed for space heating or water heating, or used in a stirling engine.
- Transportation of the fuel would not be required due to drawing power off the electrical grid. This presents significant cost benefits. Pollution created during fuel transportation would be eliminated.
- Compressed-air vehicles are comparable in many ways even to electric vehicles and their potential advantages over electric vehicles include: Compressed-air vehicles are unconstrained by the degradation problems associated with current battery systems.
- Much like electrical vehicles, air powered vehicles would ultimately be powered through the electrical grid which makes it easier to focus on reducing pollution from one source, as opposed to the millions of vehicles on the road. Compressed-air tanks can be disposed of or recycled with less pollution than batteries. The tank may be able to be refilled more often and in less time than batteries can be recharged, with refuelling rates comparable to liquid fuels.
- The tanks used in a compressed air motor have a longer lifespan in comparison with batteries, which, after a while suffer from a reduction in performance
| Item Name | Type | No. of Units | Per Unit Cost (in Rs) | Total (in Rs) |
|---|---|---|---|---|
| Total in (Rs) | 79300 | |||
| Air Compressor | Equipment | 1 | 15000 | 15000 |
| Cylinder Block 70cc | Equipment | 1 | 1500 | 1500 |
| crankshaft 70cc | Equipment | 1 | 1000 | 1000 |
| foundation | Equipment | 1 | 600 | 600 |
| Aluminum 6061 Block | Equipment | 1 | 5000 | 5000 |
| Stainless Steel Rod | Equipment | 1 | 1500 | 1500 |
| bearing | Equipment | 1 | 200 | 200 |
| Water Level | Miscellaneous | 1 | 250 | 250 |
| nut bolts | Equipment | 15 | 50 | 750 |
| Tachometer | Miscellaneous | 3 | 2500 | 7500 |
| Pipe | Equipment | 1 | 500 | 500 |
| Machining cost | Equipment | 1 | 30000 | 30000 |
| Piston 70cc | Equipment | 1 | 500 | 500 |
| transport expense | Miscellaneous | 1 | 2000 | 2000 |
| Springs | Equipment | 6 | 500 | 3000 |
| dramper | Equipment | 5 | 500 | 2500 |
| rectangular Pipe | Equipment | 5 | 1500 | 7500 |