Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: Skyguns MKII on March 19, 2014, 02:51:40 AM
-
On a turbocharged engine, Upper deck and lower deck pressure in the intake system refers to what?
-
On a turbocharged engine, Upper deck and lower deck pressure in the intake system refers to what?
:airplane: Maintaining 14.7 lbs per square inch though out the carburation system! Aircraft with normally aspirated engines lose power, which they are capable of as soon as they leave sea level altitude. The "blower" systems installed on internal combustion engines is designed to "fool" the aircraft engine in to thinking it is at sea level and depending on the kind of system and design, determines at which altitude the "blower" can continue to produce 14.7 lbs per square inch of atmospheric pressure to the carburation system. You can determine that maximum design altitude for "Blower" effectiveness by watching your manifold pressure gauge and when it starts to drop off, then you know that you have reached the maximum altitude of its assistances in maintaining a "sea level" pressure. It also permits you to fly at a much higher altitude than normally aspirated engines.
When I refer to sea level, I am assuming a standard atmospheric temperature of 59 degrees F. the changes in temperature as you climb will also effect the performance of the blower. Example, in a cold air mass, it would be more effective to a higher altitude than it would in a warm air mass, because of the density altitude!
-
My guess is
Upper would be pressure just after the throttle buttery fly valve.
Lower would be pressure of the manifold just before the piston intake valve.
HiTech
-
Upper deck pressure is the the turbocharger compressor discharge pressure. (google is your friend)
Couldn't find anything in my 2 minutes search on lower deck pressure.
-
Upper deck pressure is the the turbocharger compressor discharge pressure. (google is your friend)
Couldn't find anything in my 2 minutes search on lower deck pressure.
Lower deck is that part of the system downstream from the throttle plate.
-
I guessed almost correctly but backwards.
HiTech
-
I guessed almost correctly but backwards.
HiTech
:airplane: That's Ok, you were in the ball park. On the B-29, R-3350 compound engine, we had a 5 level carburetor, or decks if u prefer! Same Strongburg-carlson carb which was on the P&W R-4360's.
-
You are all correct! :old: i will come out with yet another question soon!
-
Even though I can't answer these, I always learn something.
-
Comparison of the two is used to check for boost leaks and restriction of intercoolers or aftercoolers which would cause a pressure drop.
This data must also include the charge temperature measured at the same points as the pressure being measured to be fully useful.
You would also have to know where the wastegate diaphragm samples it's boost reference.
-
Comparison of the two is used to check for boost leaks and restriction of intercoolers or aftercoolers which would cause a pressure drop.
This data must also include the charge temperature measured at the same points as the pressure being measured to be fully useful.
You would also have to know where the wastegate diaphragm samples it's boost reference.
:airplane: Ram air pressure is measured at the entrance to the induction system, so as to dictate how open the waste gate should be. Maximum deflection of the waste gate valve would occur when the manifold pressure began to decay with altitude! This would be a 90 degree rotation from the closed position.