AU N EGL

No not the drive up burger place with great malts.

What does the term "sonic" mean when air is moving though in intake?

is that when the speed of air hits the speed of sound and KABOOM ? What effect does this have on engine efficiancy?

Is there a way to meaure air speed inside the TB and Intake ??

and can that be changed ?? TB restrictors change that air speed.

ghoffman

Sonic means the speed of sound (I.E mach 1.0), as in supersonic is faster and subsonic is slower. It varies with the material, temperature, pressure. The speed of sound in air is different than water, aluminum etc. The airflow goes from high pressure to low pressure. Airflow through a orifice like a engine intake port cannot be supersonic because at the point it goes supersonic the pressure increases so that it is higher in the entrance and then the flow wants to reverse. Bernoulli's law states that as the velocity slows, the pressure increases, and vice-versa. This is how a carburetor venturi works, you neck it down and the velocity increases and creates a low pressure area that "sucks" the fuel out into the airstream (very much simplified example). Bernoulli's law is non-negotiable, so you can measure the velocity by measuring the pressure drop.

varkwso

Man I love this technical stuff...Bernoulli's Law, Adiabatic Principal.....

It is one of the reasons jets have variable intakes, splitters and spikes to alter intake geometry for a wide range of operating speeds....so yes you can change it but a fixed "intake" would be optimized for a certain airspeed and demand.

I am sure you could measure it several ways but pressure drop or delta P is the easiest raw reading that can be converted mathmatically into velocity - as so well pointed out above

AU N EGL

I had a conversation with some one at Katech and saw a video on the C5R engine. The term sonic also came up on this video

http://forums.corvetteforum.com/show....php?t=1503211