Help with restrictor

[98ls1]

Hey guys-

I am trying to design the restrictor venturi, and wanted to use the ASME MFC-3M standard to look up angle of arrival and departure before and after the restrictor, but our school's library apparently has had that manual stolen or lost.

Can anyone shed light on this subject for me? I understand many of you may be apprehensive about sharing restrictor design, so anything at all is much appreciated.

I am mostly curious in the angles that are tapered before and after the restriction, as well as the length of the two sides.

Again, thanks for helping a first year team and newbie.

Mike Q

University of Maryland

[98ls1]

Hey guys-

I am trying to design the restrictor venturi, and wanted to use the ASME MFC-3M standard to look up angle of arrival and departure before and after the restrictor, but our school's library apparently has had that manual stolen or lost.

Can anyone shed light on this subject for me? I understand many of you may be apprehensive about sharing restrictor design, so anything at all is much appreciated.

I am mostly curious in the angles that are tapered before and after the restriction, as well as the length of the two sides.

Again, thanks for helping a first year team and newbie.

Mike Q

University of Maryland

[Foote]

I'm not sure the angle coming into the restrictor, but a diffuser (which is what the departure angle is) shouldn't be more than 12? from center to keep laminar flow
Justin Foote
Western Washington University

[98ls1]

Anyone else? Im having a real difficult time finding the necessary info...

Thanks
Mike

[Marc Jaxa-Rozen]

12-14 degrees for total included angle sounds about right. As for inlet configuration, you might want to take a look at wind tunnel designs, most fluid dynamics handbooks will have some info about this.

Marc
École Nationale d'Aérotechnique

[Hochreiter]

I've been using "Fluid Mechanics" by Frank M. White.
The fourth and fifth edition have the same chapter 6 information that covers the total included diffuser angle friction factors.
The problem I've run into is the total volume of a plenum with a diffuser of 10* is about 466cc which is over 3/4 the engine volume.
I'm trying to determine if the diffuser acts as part of the plenum or not. If it is then the plenum is rather small.

http://fsae.com/groupee_common/emoticons/icon_smile.gif
seh

[woollymoof]

the plenum is all the volume from the throttle to the back of the intake valves.

Cheers,

Kirk Veitch
Swinburne University of Technology 2004

[Frank]

most people have a "rapid expansion" at the end of their restrictors...

be careful to keep the exit diameter at least 45mm, (or more preferably), if you have a rapid expansion there....

we use (included angles) 30 deg inlet, 60mm radius at throat, 10 deg outlet, 46mm outlet diameter.. it's a short one, making 76HP

regards

Frank