Compressed Air Car: Feasibility & Analysis

In summary: I don't think it would be worth it for you to modify your engine as it would be more expensive than buying an air motor.
  • #1
nishat
3
0
hi there,
i am studying the feasibility of compressed air to power a car as my final year project and i need some guidance.

How i proceeded:
(1) I derived equations for the driving force and consequently for the road-load power of a car, with speed as the variable.
(2) I worked backwards using data about power losses in engine and in car transmission which i assumed to be almost constant. I tabulated the indicated power and indicated mean effective pressure inside the cylinder required at different speed
(3) I then calculated the inlet pressures of compressed air required at different cut-off ratio and at different speed if the engine was to operate as a reciprocating piston air motor with 4 cyl in line such that when two pistons are doing the power stroke, the other two are performing the exhaust stroke.

My questions are :
1.Can a conventional car engine be used as a reciprocating air motor, that is, with the same piston-cylinder assembly, piston rings, connecting rod, crankshaft?
2.What about the valves?
 
Engineering news on Phys.org
  • #2
Oh no not again.
We already have a compressed air car thread, although little out of it may be useful to you since it seemed to verge on perpetual motion at times.
https://www.physicsforums.com/showthread.php?t=310462

To answer what I can.

1. Yes with extensive modifications. May not be worth it to you, since the cost of modifying is probably more expensive than an off the shelf air motor.

2. Complete rework on the valves/camshaft. A regular internal combustion engine has valve strokes that are very different from an air motor. You have to get rid of the compression phase.

Your best bet may be to use a 2 stroke diesel modified for bash valves. These have been used for steam powered setups, but should work just fine with compressed air. Or alternatively you could use existing air motors and avoid the hassle entirely.

One of these on each wheel and I think you would be in buisness.

http://www.grainger.com/Grainger/items/5KB10?Pid=search [Broken]
 
Last edited by a moderator:
  • #3
chayced said:
1. Yes with extensive modifications. May not be worth it to you, since the cost of modifying is probably more expensive than an off the shelf air motor.

2. Complete rework on the valves/camshaft. A regular internal combustion engine has valve strokes that are very different from an air motor. You have to get rid of the compression phase.

Your best bet may be to use a 2 stroke diesel modified for bash valves. These have been used for steam powered setups, but should work just fine with compressed air. Or alternatively you could use existing air motors and avoid the hassle entirely.

Hi,
I understand that it's boring to discuss the same topic, but, thanks for the reply. (i really needed help)

Luckily I am not building one; but i need to discuss these in details in my project.

1.When you mentioned 'extensive modifications', apart from lighter materials and flat piston design etc , can we use the same design of crankshaft, connecting rod. (I could not get much info about reciprocating piston air motor.)

2. If I am right, the valve strokes depend on the profile of the cams. Is it possible to replace the existing cams by new cams designed to allow the valve to open for inlet stroke until cut-off, close for power stroke (expansion), and open again for exhaust stroke? In addition, two pistons will perform the same stroke simultaneously (ex power stroke) while the other two will perform the exhaust stroke.
i have to read more about bash valves.

I read about air motors at wheels, but, do not know much about it. I calculated the input pressure of air to provide the same power output based on the existing I.C engine.
 
  • #4
nishat,

Google "MiniCAT" for all the information you would care for about compressed air motoring.
 

1. What is a compressed air car?

A compressed air car is a vehicle that uses compressed air as a source of energy to power its engine. It works by storing compressed air in a tank and releasing it to drive the pistons and turn the wheels.

2. Is a compressed air car feasible?

The feasibility of a compressed air car depends on several factors such as technology, infrastructure, and cost. While the technology exists, it is still in its early stages and there are challenges to be overcome, such as creating a lightweight and durable tank to store the compressed air. Additionally, the infrastructure for refueling compressed air cars is not widely available. However, with advancements in technology and a growing demand for sustainable transportation, it is possible that compressed air cars could become more feasible in the future.

3. How does a compressed air car compare to electric or gasoline cars?

Compressed air cars have the potential to be more environmentally friendly than gasoline cars as they do not emit any greenhouse gases. However, they may not be as efficient as electric cars in terms of energy conversion and may have a shorter range. In terms of cost, compressed air cars may be more affordable than electric cars but more expensive than gasoline cars.

4. Are there any existing compressed air cars on the market?

Currently, there are no mass-produced compressed air cars available on the market. However, there have been prototypes and concept cars created by various companies and organizations. It is still a developing technology and may take some time before it becomes commercially available.

5. What are the potential benefits of using compressed air cars?

One of the main benefits of using compressed air cars is their potential to reduce air pollution and greenhouse gas emissions. They also have the potential to be more affordable and accessible than other alternative fuel vehicles. Additionally, the use of renewable energy sources to compress the air can make them even more environmentally friendly.

Similar threads

Replies
11
Views
2K
  • Mechanical Engineering
Replies
5
Views
1K
  • Mechanical Engineering
Replies
4
Views
2K
  • Mechanical Engineering
Replies
2
Views
1K
  • Mechanical Engineering
Replies
3
Views
2K
  • Mechanical Engineering
Replies
7
Views
1K
  • Mechanical Engineering
Replies
6
Views
251
Replies
4
Views
2K
  • Mechanical Engineering
Replies
3
Views
2K
  • Mechanical Engineering
Replies
8
Views
1K
Back
Top