Tim wrote:
Are there Sonics in the Cold side of the intercooler? I
don’t think so.. Does the longer length of the hoses and the 3rd
intercooler reduce flow/pressure ?
You
are correct on not using sonic nozzles on the cold side of the intercooler. The
exit air is much cooler, and therefore under much less pressure (recall Boyle’s
Law), so full flow through the cold side tubes helps achieve a balanced flow between
hot and cold temperature selection in the cockpit. Not the “scientific”
way to achieve a flow balance, but it’s very simple and works pretty well—over
the flow rates and pressures we’re using. And to answer your second
question, the pressure and flow are not affected so much by the hose length and
long flow path—which do contribute somewhat. The drop in temperature is
responsible for the majority of reduced pressure/flow through the cold side.
To
answer another question posed by an LML contributor: the concept of a “sonic”
nozzle is that when the air passing through the nozzle reaches supersonic flow,
it sets up a shock wave in the throat that effectively “throttles”
the flow. This causes the nozzle to flow a relatively constant volume of air
over a wide range of input pressure-once the flow reaches supersonic in the
throat. Without these, you’d see a very abrupt change in cabin in-flow
and pressure every time you move the throttle of your turbocharged Continental
while the cabin pressure controller—a rather slow-acting device, struggles
to keep up with the changes. If you install the sonic nozzles backward, they
won’t work as intended, the flow will be closely proportional to the
input pressure.
Hope this helps.
Bob Pastusek