Does anyone know or can calculate? - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Insert BS here A place to discuss anything you want

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 03-21-2008, 07:20 PM   #1
Elite Member
Thread Starter
iTrader: (3)
 
Mach929's Avatar
 
Join Date: Oct 2004
Location: lansdale PA
Posts: 2,500
Total Cats: 0
Default Does anyone know or can calculate?

how much heat any given intercooler can dissipate without air flowing throught it? estimates? in other words looking for an intercoolers effectiveness when it isn't placed with air flowing directly through it.
Mach929 is offline   Reply With Quote
Old 03-21-2008, 07:45 PM   #2
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago (Over two miles from Wrigley Field. Fuck the Cubs. Fuck them in their smarmy goat-hole.)
Posts: 26,317
Total Cats: 1,913
Default

After it heatsoaks? None.

Well, almost none. There will be a tiny amount of radiant dissipation, assuming the surrounding environment is cooler than the air coming out of the compressor.

This kind of question begs a more detailed explanation.
Joe Perez is offline   Reply With Quote
Old 03-21-2008, 08:10 PM   #3
Hittin' Boost & Cones
iTrader: (2)
 
240_to_miata's Avatar
 
Join Date: May 2007
Location: Cromwell, Connecticut
Posts: 2,572
Total Cats: 11
Default

your talking about summing up about 3 different thermodynamic mechanical engineering classes into one answer. I wish i could answer this, but ive barely touched on heat exchangers so far...
240_to_miata is offline   Reply With Quote
Old 03-22-2008, 12:03 AM   #4
Elite Member
iTrader: (12)
 
Join Date: Jan 2007
Location: Hermosa Beach, CA
Posts: 2,575
Total Cats: 11
Default

well im still in high school but..

with no air flow, when you start the car, the intercoole will be at amibant temp. Thus it will cool the intake charge to this temp untill the intake charge gets the intercooler hotter and hotter untill they are the same (heat soaked). at that point the only thing cooling the intercooler would be the temp difference between the intake charge and the outside air, but since the outside air is still, the intercooler is not dissapateing much heat.

Of course if the intercooler was HUGE it would work better....
cardriverx is offline   Reply With Quote
Old 03-22-2008, 12:14 AM   #5
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago (Over two miles from Wrigley Field. Fuck the Cubs. Fuck them in their smarmy goat-hole.)
Posts: 26,317
Total Cats: 1,913
Default

Fill the "atmospheric" portion of the core with paraffin wax, and seal it completely.
Joe Perez is offline   Reply With Quote
Old 03-22-2008, 12:22 AM   #6
Senior Member
iTrader: (1)
 
Join Date: Apr 2007
Location: North Jersey
Posts: 721
Total Cats: 0
Default

ummmmm......why the hell would you bother with an air/air intercooler if you didn't have airflow? seems pointless.

as the rest said.....it'll probably have some effectiveness until it's temp comes up to charge temp.
budget racer is offline   Reply With Quote
Old 03-22-2008, 02:02 AM   #7
Senior Member
iTrader: (5)
 
Join Date: Nov 2007
Location: Troy, MI
Posts: 860
Total Cats: 13
Default

unless the intercooler is placed inside of the engine bay where it has no access to ambient airflow, is it even possible that "heatsoak" can occur? Isnt this term more relevant to water-air intercoolers?
The_Pipefather is offline   Reply With Quote
Old 03-22-2008, 02:19 AM   #8
Elite Member
Thread Starter
iTrader: (3)
 
Mach929's Avatar
 
Join Date: Oct 2004
Location: lansdale PA
Posts: 2,500
Total Cats: 0
Default

Quote:
Originally Posted by The_Pipefather View Post
unless the intercooler is placed inside of the engine bay where it has no access to ambient airflow, is it even possible that "heatsoak" can occur? Isnt this term more relevant to water-air intercoolers?
well this is more or less what i'm asking, if an intercooler was placed in a position where air was turbulent around it but not necessarily flowing though it, what are the effects? aka smic with no ducting? If ambient temp is 75 degrees and charge temp is 140, there's pretty much no way inlet temps will be 140 regardless of air flow through the intercooler. i'd like more discussion here as i'm not sure of all the forces at play since i stopped studying engineering 8 years ago
Mach929 is offline   Reply With Quote
Old 03-22-2008, 11:45 AM   #9
Senior Member
iTrader: (14)
 
Join Date: Aug 2007
Location: Buffalo, NY
Posts: 734
Total Cats: 1
Default

Quote:
Originally Posted by The_Pipefather View Post
unless the intercooler is placed inside of the engine bay where it has no access to ambient airflow, is it even possible that "heatsoak" can occur? Isnt this term more relevant to water-air intercoolers?
Heat soak is a problem generally associated with top-mount intercoolers (as are stock on turbo Subarus) and water to air ic's.

A properly sized, properly designed front mount setup should not have heat soak issues.
deliverator is offline   Reply With Quote
Old 03-22-2008, 12:11 PM   #10
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago (Over two miles from Wrigley Field. Fuck the Cubs. Fuck them in their smarmy goat-hole.)
Posts: 26,317
Total Cats: 1,913
Default

I really think the only way you're going to figure this one out is by experimentation. I don't recall anything from Thermo or Properties of Materials that would be of much use in calculating the rate of heat transfer from a metallic body of complex and unknown and complex geometry into a surrounding body of turbulent air moving at an unknown velocity and direction.

If there is, in fact, zero airflow through the core, then upon seeing increased charge temps, the intercooler will initially absorb a great deal of heat out of the intake air, gradually rising in temperature itself. As this occurs, the rate of heat absorption will decrease, rapidly approaching zero. After the charge temps drop back down, the intercooler will begin transferring heat back into the intake airflow, cooling itself down to the temperature of the intake air. The rate at which this takes place will depend largely upon the mass of the intercooler, but we're talking seconds, maybe fractions of a second.

If there is "some" airflow through the core, then there will be "some" heat exchange away from the intercooler, into the atmosphere.

Is there a practical reason for this? I think we can all agree that it's going to be non-optimal, and that depending on the constraints that preclude a traditional FMIC to begin with, some other solution such as a water-air intercooler might be a viable alternative.
Joe Perez is offline   Reply With Quote
Old 03-22-2008, 01:03 PM   #11
Elite Member
Thread Starter
iTrader: (3)
 
Mach929's Avatar
 
Join Date: Oct 2004
Location: lansdale PA
Posts: 2,500
Total Cats: 0
Default

lol i have a fmic on my miata. But i've seen people with ghetto setups go as far as mount an intercooler in the engine bay, i'm just wondering how well it could work, obviously i know it isn't optimal, then i've seen oems smic intercooler solution and i just can't imagine they're getting all that much air through it. Then i've seen STS turbo kits that are rear mount turbo and just run a pipe from the rear of the car to the front stating that that is sufficient to cool the charge. I'm not at all knocking a good ole fmic intercooler setup i was just curious.
Mach929 is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Foreign powered NB for NASA ST3 and/or E0 d k Race Prep 44 09-15-2015 11:59 AM
Interpreting Deatchwerks Dead Times from Battery Wizard compuw22c MEGAsquirt 0 09-14-2015 07:08 PM
ME221 Now has Autotune and Long Term Fuel Trim Tables Motorsport-Electronics ECUs and Tuning 0 09-05-2015 09:02 AM
Idle pulse width calculation mnelson MEGAsquirt 0 05-24-2009 01:38 AM
Compressor Map Calculations (are frustrating) oilstain DIY Turbo Discussion 18 07-08-2008 06:12 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 07:08 PM.