Originally Posted by
PBBIZ2
God, this is digging deep and on my third scotch and ice, its becoming difficult!!!
The air is only going to be compressed based on the flowrate down the tube and the resultant pressure - bearing in mind in this situation that pressure is simply system resistance as we don't have a positive compressive device like a fan or pump - itsd whatever air is flowing based on vehicle velocity into the end of the hose. Without a fan as such this is heading towards lab grade measurement device and well beyond what the mere mortal could afford.
If you had your DP device without a hose it will still detect the pressure difference, but may not indicate it unless the scale/sensitivity is correct, and unless the volume of air is significant you wont see the pressure build up in your compressible medium, so again, very small airflow is a problem. Its possible to detect very small pressure differences with a pitot tube, laid over on the side and measuring 'hundredths of an inch wg', but hard to steer down the road and not crash at the same time.
If this was water or incompressible we would be laughing for sure.
What you could do is measure the DP across the intercooler coil. The question then is whether this DP can be related to cooling capacity. The variables from a mechanical sense would be it the flow rate high enough butthe PD across the coil too great to effectively strip the heat out of the air, or is the flowrate too low to allow the coil to operate effectively. I dont know the answer as these are really design related issues - so in essence you need to find out the flow rate required, at what temperature range, the efficiency curve matches the intercooler at. The DP then is the design element that relates to the efficiency of the heat transfer device - I think thats clear??? So if the DP is too high the cooling effect is lower, if the differential temperature between the cooling air and the 'to be cooled air' is too close the efficiency drops also.End of the day its heat energy being transferred by whatever method is in play.
My glass is empty, going for a re-fill.