Posted on: 11-12-14 11:08:13
I am looking for some numbers on the exhaust flow rate from gasoline (petrol) cars. I cant find in the testing centres here in India as they don't need to measure it.
Say for a average speed of 20-25 km/hr, what could be the ballpark flow rate from the exhaust? Lit/sec or any unit is fine. I am working on a project related to pollution form vehicles.
Exhaust flow rate will depends upon rpm and size of the engine. It has no relation with the pollution. To get the pollution measurements, you need to analyze the affluent.
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A Delhite in Toronto
Thanks. Is there a relation (formula?) between RPM and velocity/flow rate?
Quote:
Originally posted by MKBLR
Thanks. Is there a relation (formula?) between RPM and velocity/flow rate?
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Here is a little help... :
Work with it and if you have more questions, AND hope it is not about Thermodynamics, and even if it is, i will walk you
through Khan's Academy and provide you with all of the basic
knowledge on the subject matter, till you grasp the subject
that we are going to explore here..
First you will get to know about the 4 cycle engine, the one that we all drive on the road. There is one power stroke and three other strokes that just complete the cycle. Other three strokes needed to complete, to give you a 4-cycle system. (4 Stroke engine) This has a slightly more efficient system than the two stroke Engine.
http://en.wikipedia.org/wiki/Engine_displacement
Once you get to know about these cycles.... also get to know..
http://en.wikipedia.org/wiki/Variable_displacement
Generally, the efficiency of a 4 stroke engine is about 32% and upwards. Currently it has gone upwards of 40%. In short if you are paying Rs.80 per liter for gasolene, or petrol, then you only are using 32 rupees for driving. The rest goes up into smoke or the exhaust or the EFFLUENT.
Now you seem to know all or most of it. So, work with it. If you want to know more get back.
FH.
Thanks FH.
I am writing a proposal to test flow rate and exhaust pollution in a car. Use a hatch back car, open the back, keep the instrument(s) and have the hand held instrument clipped near the exhaust. Not sure if it works or not. At least I want to try it out. Travel for abt a km. Get the flow rate and ppm values of the pollutants in the exhaust. Then calculate the pollution.
Quote:
Originally posted by MKBLR
Thanks FH.
I am writing a proposal to test flow rate and exhaust pollution in a car. Use a hatch back car, open the back, keep the instrument(s) and have the hand held instrument clipped near the exhaust. Not sure if it works or not. At least I want to try it out. Travel for abt a km. Get the flow rate and ppm values of the pollutants in the exhaust. Then calculate the pollution.
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First, You know the car well. You also know the number of cylinders and the volumetric capacity of a cylinder. The type of cycle, and then the RPM and the number of cylinders it has. (This is the tricky portion.) Some have Tachs but will only provide you with the distance traveled, in kilometers. Now comes the Gear Ratios and the gear level you are driving the vehicle at. That way you know that Engine running at a specific speed and in a gear that you are driving, will provide you with the distance traveled.
If you know the TYRE and its circumference, you can divide the distance traveled by the Circumference of the tire to give you the RPM that you traveled and the gear ratio and the engine RPM will give you the efficiency of the system. That will be the Engine Efficiency with a tire slippage.
What we do is, run it in an Environmentally controlled area, on a Dynamometer, with the exhaust being removed through an opening in the door, which will blow it out of the area and into the open, where you are testing.
All of these instruments are available in many schools, and colleges, and also with the Research Labs and also in the Car manufacturers' plant. See who will help you test this idea and for how long.
Newer Vehicles with latest of Platinum Exhaust Gas Coverter, will tell you how well they are made and how good they are functioning.
Here in Canada there are facilities that do the e-testing of the vehicles and they also have the facilities to tune the engine and also advance or retard the firing cycle to provide you with an ideal running condition for a certain speed, say 100 km/hr. If you hold that speed and you can see how the computer that is provided to you on board, functions, you will know the performance. The newer vehicles have them.
Good Luck.
Hope this will help you a little,
FH.
I am not going into details for the pilot. I will just get a Tata Indica diesel and run it with instruments in the back. IMO, Indian laws are biased against petrol cars though diesel exhaust is more dangerous to health than petrol, as per WHO studies. For diesel vehicles, they test only the colour of the smoke whereas for petrol they test for carbon monoxide, CO2 and Hydrocarbons. Many testing centres have failed audit of the govt reg equipment and staff.
