I am a mechanical engineering student and I have to do a design project on a heat exchanger. Since I'm obsessed with my car I want to design an intercooler for the WRX. I want to make it as accurate as I can so that my results will be useful, but I need help obtaining data for the I/C system.

Basically all I have off the top of my head is the peak pressure out of the turbo. I'll be analyzing the system at WOT, so a graph of turbo pressure vs. engine speed would be incredibly helpful.

There are two flows in the intercooler, hot and cold ( I figure most already know this stuff, but maybe it will help some) The hot flow, from the turbo is cooled by the cold flow from the scoop. Now all I need is the mass flow rates for the hot and cold and the temperatures at the input and output for each flow.

My assignment is to design the intercooler, but I would like to analyze the stock unit to determine if upgrading the intercooler is effective with the stock turbo. I'll also find what the difference is between the stock and STi hood scoops.

I was wondering if some of the ECU products out there can log the type of information that I'm looking for. Any help at all is greatly appreciated.

--Alex

 

sorry I cant help ya, but post the results when ya get em please

 

Some info that may help here:

http://www.scoobymods.com/forums/sho...&threadid=2302

 

this is a thermo/heat transfer problem. so hopefully you have already taken heat transfer and thermo 2.

those diagrams that peaty posted gives you the temperatures that you are looking for.

is this a year long project? cause if i am understanding this correctly, it will take a long time.

 

I have taken Thermo 1, Thermo 2, Heat Transfer 1, and this project is for my Heat Transfer 2 class. I have until the end of the semester to do it, about three months. The project is supposed to be roughly 40 hours.

Thanks for the graphs.

 

I've sent emails to subaru, Vishnu and Cobb. Subaru can't help and I haven't heard back from the other two...

Does anyone know if it's possible to acquire data using one of the various piggyback ECU's? and if so which one?

looking for flow rate vs. car speed
and turbo pressure vs. engine speed

Thanks

 

I don't think I can realistically or accurately gather all the data I need given my resources. I plan on designing the intercooler for max flow rate of the turbo, which is perfectly fine with me. I'm modelling it as a simple open system, operating at steady state. So if anyone knows what flow rate is at peak boost (stock), please let me know and please state your source so I can cite it in my report.

I have temperatures in and out of the turbo and intercooler, and the mass flow rate through the intercooler.

Using the equation Qdot=mdot(h2 - h1)

where Qdot is rate of heat transfer
mdot is mass flow rate
and h is enthalpy (function of temp)

edit: I will calculate mass flow rate through the intercooler as a function of velocity with mdot = density*Area of scoop*velocity.

With this I can show some nice graphs and compare the sti scoop to the stocker

--Alex

 

Just an update/bump here. I mistakenly stated that I know the Temp out of the I/C in the above post. I don't know that so I did my calcs using the effectiveness-NTU method.

The stock I/C is a fin and tube design, but the tubes are elliptic with fins inside (see pic). This is not the best geometry from what I have read. So for the design I will use a plate and fin setup. As you can see I've run in to quite a few hang ups and now I've got two days to finish. I also have test in my Fluids class the day this is due so I'm basically screwed now. Okay now I'm just ranting and it's 2 in the am.

I guess I have all the info I need thanks to i-Club and nasioc. So thanks everybody.

 

APS intercooler

plate and fin type. Layers of fins with different orientation to allow for cross flow.

 

Another update as if anyone is reading this thread. Well it makes me feel special.

The effectiveness NTU method is out. I did an iterative solution with the log mean temperature differential method. Which means I guess at the temp of the flow out of the IC on the cold side until I achieve an aprropriate effectiveness. Word!