MONZTER Posted March 30, 2008 Share Posted March 30, 2008 It seems like there has been alot of talk about the pluses and minuses of the different intercooler configurations for our Z cars. Which is better? Same side inlet and outlet, or opposite side? That’s for another post that has been debated over and over. What I wanted to show was my decision, and what I have found out, and how I have modified it to make what I think is a good solution to an efficient design. My decision was to go with the inlet and outlet on the same side, as I really wanted the shortest possible tubing, not to mention what I believe to be a intercooler with less pressure drop. So I ordered up a Custom sheet metal tank Spearco unit 18x6x3.5 , only to be really disappointed when it showed up, as I have seen better looking agriculture equipment. The inlet and outlet were just butt welded on with no regard to smooth airflow, and the ends were cut nearly square, again not really smooth creative work. Here is a pictures of the stock unit as delivered from Spearco. We have all heard talk of how this type of intercooler recycles the air inside, in a circular motion near the inlet and outlet. Also, it is known as not being very efficient to cooling, because all the air gets pushed to the end of the tank, not letting the air flow evenly through the core. So I modeled it up in Pro-E and set to work doing some CFD flow testing on it for a little look. The test was done very simply, ambient on the inlet side and 25" on the outlet side. I wanted to test total CFM flow as well as pressure drop and distribution of the air. Please keep in mind this is only a quick test and the core is correct in dimensions, but obviously no tubulators, So look at the info for what it is, a comparison between one test and another, not between this test and a actual unit. So you can see in this picture first off is a recirculation effect. The air enters in the bottom inlet, up through the core, out, back down the core, back up the core... click to enlarge the picture and look at the flow arrows. Next is the pressure plot- Finally the velocity plot. So now on to the modifications. First off is the inlet and outlet. I made nice square to round transitions 2.5" inlet and 3" outlet. No longer is there a sharp square edge right before the outlet, you can see the effect on the pressure plot above. Next, I made smoother tapering sections at the end of the plenum. Finally, I made divider plates to basically split the Plenum into two halves, hopefully improving the balance of flow, fixing the recirculation problem, increasing the heat rejection and thus efficiency. Check out the arrows - no more recirculation Pressure plot shows the air is being distributed more evenly through the full core, not just he ends. The smooth inlet and outlet also show the lack of a high pressure flow reducing area right before the outlet. Check out the velocity. The air seems to stay more consistent in speed, I assume this is why there is a little more pressure drop. Check out the numbers. An increase of 162CFM through the same core. So what do you think? Does it look like it all makes sense? Jeff Quote Link to comment Share on other sites More sharing options...
hughdogz Posted March 30, 2008 Share Posted March 30, 2008 You never cease to AMAZE Monzter!! 41% more flow is quite an impressive improvement. Quote Link to comment Share on other sites More sharing options...
Flexicoker Posted March 30, 2008 Share Posted March 30, 2008 Nice work, what did you use for CFD? Very pretty welds too. Quote Link to comment Share on other sites More sharing options...
zguy36 Posted March 30, 2008 Share Posted March 30, 2008 Did you do any calculations to see if you are getting flow separation on the trailing end of your divider on the inlet side? If that is the case, you are introducing a lot of turbulence into the rear section of the intercooler. I did notice that there were very few flow traces through the first few tubes. In any case, that is a ton better than the "as-purchased" design. Now, the real question is, why didn't you just buy a core and make your own stuff if you can do that good of work! Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted March 30, 2008 Share Posted March 30, 2008 Very nice test and nice fabrication work. Quote Link to comment Share on other sites More sharing options...
ihatejoefitz Posted March 30, 2008 Share Posted March 30, 2008 Why the asymmetrical plenums? Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted March 30, 2008 Administrators Share Posted March 30, 2008 You crack me up Jeff... you create that which belongs in the Smithsonian, equally at home in the Fine Art dept. AND Science & Technology... and then install it on a old Datsun... I love it! Thanks for sharing. Quote Link to comment Share on other sites More sharing options...
MONZTER Posted March 30, 2008 Author Share Posted March 30, 2008 Nice work, what did you use for CFD? Very pretty welds too. The software is Cosmos Floworks, I think it’s at its limits with the narrow fluid space in the core. The company I work for just bought CD-Adaptco Star CCM+ and Star Pro-E for our external flow models, seems much more capable as it is the same software used by the F-1 teams. I will re-do some of these test with the new software after I get some training. http://www.cd-adapco.com/products/STAR-CCM_plus/index.html Quote Link to comment Share on other sites More sharing options...
MONZTER Posted March 30, 2008 Author Share Posted March 30, 2008 Did you do any calculations to see if you are getting flow separation on the trailing end of your divider on the inlet side? If that is the case, you are introducing a lot of turbulence into the rear section of the intercooler. I did notice that there were very few flow traces through the first few tubes. In any case, that is a ton better than the "as-purchased" design. Now, the real question is, why didn't you just buy a core and make your own stuff if you can do that good of work! Yep I am getting some turbulence in the dead spot where the first and second halves of the core are separated. I will post a close up of that section so you can see it better soon. It’s not perfect, but as you said a lot better than what it was, and I will have to be just happy with that. I actually have plans to make my own tanks from scratch for my next build, and they will eliminate this problem, I just wanted to salvage the intercooler I already bought. I bought it in the first place because I am getting tired of my car never being finished, and I thought I would save some time by having one built. Well after getting it I couldn’t just leave well enough alone. Quote Link to comment Share on other sites More sharing options...
MONZTER Posted March 30, 2008 Author Share Posted March 30, 2008 Why the asymmetrical plenums? For just the reason stated by Zguy36 above. I thought a bigger taper in the bottom would help even out the flow in the second half of the core and eliminate any dead spots. I knew what direction the air was flowing so I figured a little more room on top would keep the velocity more consistent. I think most intercoolers are symmetrical because they are universal fit and you can then run the air in any direction you want. Quote Link to comment Share on other sites More sharing options...
MONZTER Posted March 30, 2008 Author Share Posted March 30, 2008 You crack me up Jeff... you create that which belongs in the Smithsonian, equally at home in the Fine Art dept. AND Science & Technology... and then install it on a old Datsun... I love it! Thanks for sharing. Thanks Ron, Even better is that my old Datsun still has the original paint and rust. It makes it that much more fun not having to worry about some pretty paint. Quote Link to comment Share on other sites More sharing options...
Evan Purple240zt Posted March 30, 2008 Share Posted March 30, 2008 Man what a beauty. I love it when people do mods with modeling. So much more entertaining to see whats happening beyond theory. Those stock end tanks were awful Quote Link to comment Share on other sites More sharing options...
Flexicoker Posted March 30, 2008 Share Posted March 30, 2008 Awesome, I'd like to know how you like it. I have used FloWorks a little bit, and we just got a license of Star CCM+ as well. I have yet yo play with it though. The software is Cosmos Floworks, I think it’s at its limits with the narrow fluid space in the core. The company I work for just bought CD-Adaptco Star CCM+ and Star Pro-E for our external flow models, seems much more capable as it is the same software used by the F-1 teams. I will re-do some of these test with the new software after I get some training. http://www.cd-adapco.com/products/STAR-CCM_plus/index.html Quote Link to comment Share on other sites More sharing options...
jeffer949 Posted March 30, 2008 Share Posted March 30, 2008 A little on a side note but what do you think of this intercooler.http://cgi.ebay.com/ebaymotors/TURBO-INTERCOOLER-18x6x3-5-DSM-ECLIPSE-TALON-7MGTE_W0QQcmdZViewItemQQ_trksidZp1742Q2em153Q2el1262QQcategoryZ33742QQihZ015QQitemZ250230745867QQtcZphoto Same size with somewhat similar end tanks. Would it benefit from having the divider welded into place? If you would be interested in some more measurements I will be be getting this on Tuesday. Quote Link to comment Share on other sites More sharing options...
ShaggyZ Posted March 31, 2008 Share Posted March 31, 2008 Looks great, but it almost seems like running twin intercoolers of the same total size as that intercooler would be more efficient - maybe a twin entry single exit intercooler? Obviously, using a correct leading edge (ie air-foil) for the y-pipe would be important. I've been scheming twin intercoolers and multiple small radiators in my head for awhile. Still, I really admire your engineering and welding. If twins aren't in the cards for me, I'll definitely consider having some custom end-tanks worked for me. Quote Link to comment Share on other sites More sharing options...
Careless Posted March 31, 2008 Share Posted March 31, 2008 i always wondered why they didnt separate the air charge in two on those designs! i mean, just looking at it from the outside, I could never understand what made the second half, or last third of the intercooler even worth having there. the air would loose so much velocity i that area, that making a turn into the fins would be a chore for them. i'm glad you did this mod and posted concrete results Quote Link to comment Share on other sites More sharing options...
ShaggyZ Posted March 31, 2008 Share Posted March 31, 2008 What do you think about the type that most people run now - the general, large front mount intercoolers that are 15" tall with the inlets running directly facing into the core, either at the top, middle, or bottom (don't think it matters)? Pull off half those tubes and you've probably got a more efficient (size-to-cooling/flow) intercooler. In fact, I love(d) my Porsche 944 intercooler that was a 6"X6" block that was about 20" long and, with the end-tank design, uses the entire intercooler efficiently. Just sold it today to a turbocharged '75 Stingray running straight propane I hardly understand fluids, but I'm thinking most of the bottom of those intercoolers don't get used at all. However, I think if the end tank inlet is aimed in such a way as to direct the air down perpendicular to the tubes, then that is much more efficient. I'm thinking asymmetrical end tanks are the way to go, by the way. EDIT: check out http://www.bellintercoolers.com/ and their end-tank designs and consider what MONZTER has shown us. Lots of funky end-tanks: asymmetrical, dual-inlet-single-outlet (vice-versa?), sticking with shorter but thicker cores(?) EDIT AGAIN: What effect would simply flipping one end-tank on MONZTER's intercooler (minus the splitters) have on flow, efficiency, turbulence? i always wondered why they didnt separate the air charge in two on those designs! i mean, just looking at it from the outside, I could never understand what made the second half, or last third of the intercooler even worth having there. the air would loose so much velocity i that area, that making a turn into the fins would be a chore for them. i'm glad you did this mod and posted concrete results Quote Link to comment Share on other sites More sharing options...
MONZTER Posted March 31, 2008 Author Share Posted March 31, 2008 A bunch of good post and questions. The purpose of my initial test was to see if I could make the intercooler I already purchased better. I think I succeeded. If I had to do it again, I would not buy the same set-up and modify it. I would go for a completely different tank design that doesn’t flow the air perpendicular across the core in the first place. Have you guys ever seen this site? http://www.gurneyflap.com/bmwturbof1engine.html Some of the old F-1 cars are great inspiration Quote Link to comment Share on other sites More sharing options...
Noddle Posted March 31, 2008 Share Posted March 31, 2008 I knew I saw your design from some where else, the book "Maximum Boost" has a section on intercoolers, I copied this. Quote Link to comment Share on other sites More sharing options...
MJLamberson Posted March 31, 2008 Share Posted March 31, 2008 Patent the design then show spearco Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.