What is the Velocity of Air Entering the Air Filter?

In summary, you are analyzing an air filter and trying to find a way to calculate the velocity of the air. You are also trying to find a way to calculate the power lost due to the air velocity.
  • #1
emKhairol
9
0
Hello guys,

I just came out with a new idea for my thesis project which is to improve the air filter system (drop-in type).

Currently I doing some basic analysis based on the current stock air filter before I proceed to my prototype air filter system.Says, I've been given an air filter which the area is 0.25m X 0.15m = 0.0375m^2.

I assumed the ρ of the air at average temperature (27.5 C ≈ 300 K) is about 1.161 kg/m^3.

We already know that, mass flow rate = (density)(volumetric flow rate) = (density)(area)(velocity)Based on the data given above, how can I determine the velocity of the air going inside the air box?
- there are several unknowns volumetric flow rate, mass flow rate

By using this equation, velocity = (volumetric flow rate) / (area) can I assume the velocity of the air is the same with the velocity of the car? (its seems like the velocity of the air (in m/s) too big.

Hope our engineers and pros may help me by solving this problem together. Thanks.***sorry for my bad language. I trying to make it clear for better understanding***
 
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  • #2
without going into a lot of emperical data here are a few things to think about...
todays vehicle design limits where cold air can be piped into todays engine room. With this limiting factor we have to use the air channel as manufactured. Heat is the biggest robber of HP on the intake side. If memory serves me I think at wide open throttle we are moving 40 pounds of air per minute (500cfm). Dyno results tell us we will LOOSE horsepower if we remove the intake air filter...surprise..but true...

I'll post the reason after we all think about how this can be...

as far as air velocity..pretty much vehicle dependant relative to speed and location of the intake inlet...the hot setup is to locate it in hugh pressure area to improve performance...K&N air filter are the number one supplier in th espeed world and have done mucho research on this issue..hope it helps
 
  • #3
Ranger Mike said:
without going into a lot of emperical data here are a few things to think about...
todays vehicle design limits where cold air can be piped into todays engine room. With this limiting factor we have to use the air channel as manufactured. Heat is the biggest robber of HP on the intake side. If memory serves me I think at wide open throttle we are moving 40 pounds of air per minute (500cfm). Dyno results tell us we will LOOSE horsepower if we remove the intake air filter...surprise..but true...

I'll post the reason after we all think about how this can be...

as far as air velocity..pretty much vehicle dependant relative to speed and location of the intake inlet...the hot setup is to locate it in hugh pressure area to improve performance...K&N air filter are the number one supplier in th espeed world and have done mucho research on this issue..hope it helps


Thanks for your detail explanation. From your words, you saying that the air moving at 40 pounds per minute, it means that was the mass flow rate isn't? So that, if convert to SI unit it will be 0.3023949 kg/s.

***correct me if I wrong*** :blushing:
 
  • #4
emKhairol said:
Based on the data given above, how can I determine the velocity of the air going inside the air box?
The velocity and therefore mass flow rate are arbitrarily chosen based on the cooling requirements and therefore the size of the fan.
By using this equation, velocity = (volumetric flow rate) / (area) can I assume the velocity of the air is the same with the velocity of the car? (its seems like the velocity of the air (in m/s) too big.
No. The air circulated through the cabin is circulated by a fan.

[Edit] Er, wait -- I guess you are talking about the engine air filter, not the cabin air conditioning filter. In that case, the air velocity/volume is determined by the intake of the engine. Similar concept to a fan, though.
 
  • #5
russ_watters said:
Er, wait -- I guess you are talking about the engine air filter, not the cabin air conditioning filter. In that case, the air velocity/volume is determined by the intake of the engine. Similar concept to a fan, though.

Thanks for your answer. And yes, I'm talking about the engine air filter (not the air-conditioning filter). :smile:

By the way, I'm counting the amount of air velocity/volume just before the air pass through the MAF sensor. In other word, the air flow into the filter. ***sorry for my bad language if you don't understand it***

The simplest way like this :

AIR (at state 1) --->>> AIR FILTER --->>> AIR (at state 2) --->>> MAF SENSOR --->>> AIR INTAKE
 

1. What is an air filter and how does it work?

An air filter is a device that is used to remove particles and pollutants from the air. It works by trapping these particles in the filter media, which can be made of various materials such as fiberglass, foam, or pleated paper. As the air passes through the filter, the particles become trapped and clean air is released back into the environment.

2. Why is it important to regularly replace air filters?

Regularly replacing air filters is important because over time, they can become clogged with trapped particles and pollutants, making it difficult for air to pass through. This can decrease the efficiency of the filter and lead to poor air quality. Additionally, old and dirty filters can also put strain on your HVAC system, potentially causing it to work harder and use more energy.

3. How often should air filters be replaced?

The frequency of air filter replacements depends on various factors such as the type of filter, the amount of pollutants in the air, and the usage of the HVAC system. In general, it is recommended to replace air filters every 3 months, but it may need to be done more frequently in high-pollution areas or if the HVAC system is used frequently.

4. Can air filters improve indoor air quality?

Yes, air filters can improve indoor air quality by trapping pollutants and particles that can be harmful to our health. They can help reduce allergens, dust, and other contaminants in the air, making it cleaner and safer to breathe. However, it is important to note that air filters are not a substitute for proper ventilation and cleaning.

5. What are the different types of air filters available?

There are several types of air filters available, including fiberglass, pleated, electrostatic, and HEPA (High Efficiency Particulate Air) filters. Fiberglass filters are the most common and are typically the least expensive. Pleated filters offer better filtration and are more efficient, but they are also more expensive. Electrostatic filters use static electricity to trap particles, and HEPA filters are the most effective and can trap particles as small as 0.3 microns in size.

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