Sidepods....

[Joy Pathak]

Just wanted to start a discussion on Sidepods alone. Didn't see much anything in particular on it in the threads.

Just wanted to know people opinions on a few things...

Are sidepods needed?
If they are...
Other than aesthetics...
What else have teams done with them other than positioning rads. Are there universities running channels and ducts in their sidepods for cooling engine area/ brakes and such?

Is anyone running a sidepod system kinda similar to the lotus 79 car? If so.... What kinda gains have you guys seen with it alone?

What about Mini-pods on top of the sidepods ?

What kind of configerations do most universities run on their sidepods... As in... Big...small...long... tight... slotted.... open front and back... Mesh on the openings... etc etc.

I am really hoping some UTA/ Monash/ Helsinki and Missouri team members to post something. They have some really good functional sidepod designs.

[Kai69i]

Hi Joy,
This is the last post I wanted to see after clambering out of the University's Wind Tunnel, solely gathering data on sidepod design for the last two days! But anyway, I'll give you some advice on what we have found.

Firstly, in forms of motorsport such as F1, sidepods are absolutely unnecessary for cooling purposes; they are solely a drag reduction device (however they also serve as a crash crumple zone). Hence, when you see the cars at places like Bahrain in the warmer conditions, they have cooling fins and chimneys all over the body work (much more open configuration). Basically, there is a trade-off between cooling efficiency and drag minimisation- more openings yields better cooling efficiency but increased drag, and sealing the heat exchanger away within a closed sidepod yields less cooling efficiency but minimal drag. You really need to think about what you are trying to achieve...... In my opinion for FSAE competition, it is merely a trade-off between aesthetics and cooling efficiency; drag minimisation is a waste of time purely for sidepods, unless you are looking at parametric optimisation of your entire car (and even then it is probably a waste of time!).

Traditional theory dictates that you would run a smaller cross sectional entry to the sidepod, which would be gradually increased to the largest cross section where the radiator is positioned for optimal cooling (reduce the velocity and hence increase the static pressure for optimal cooling). However, you will probably find that you encounter some problems should this entry cross section be too small. My advice would be to run as large as you need- the more air getting in, the better in our slow speed competition.

Here is the big tip for optimal cooling efficiency in FSAE cars- minimise recirculation of the air within the sidepod (both on entry and exit). I wouldn't recommend sealing all the sides/top/bottom of the radiator in the sidepod- as this will make the air ˜spew' out of the front of the sidepod, and reduce cooling efficiency. However, I also recommend that you don't leave all sides/top/bottom open, as this will have other adverse effects. Have a play in the wind tunnel and see what you come up with.

Perhaps the most important aspect for cooling efficiency is a nice distribution of the flow through all segments of the radiator. Put a probe at the top and bottom of the radiator in the wind tunnel, and find a configuration which gives consistent results top and bottom.

If there is one thing F1 has taught us, it's that sidepods only take flow in next to the chassis (hence the triangular shape of the entry ducts on all cars now). Many teams are also running inverted wings next to the cockpit now (such as the Ferrari), which draw more flow into the sidepods (have a think about the Bernoulli Equation on that one). This is something I would personally think about, as one team which had similar devices on their front A-arms at the recent UK Formula Student event claimed it produced a 10% increase in cooling efficiency. Our tests have also indicated that this is the case.

We run an inboard brake on the rear of our car, which doesn't require any ducting. A 150kg car also doesn't tend to work the brakes very hard, but some of the teams running a 4 cylinder may be feeding the rear brake ducts via the sidepods (I'm really not sure). Ventilation of the engine bay is probably wise via the sidepod- but duct it from right next to the chassis.

The bottom line: If you want optimal cooling efficiency and are not worried about drag (or aesthetics), run your radiator at an angle of about 70 degrees in the open (no sidepod at all). If it is aesthetics and the Design Event you want to win, run the radiator in a short sidepod with a large opening!

Cheers,

Kai

[Christopher Catto]

Originally posted by Kai69i:
run your radiator at an angle of about 70 degrees in the open (no sidepod at all)
Kai

funny you say that. I thought it would have been hopeless. we ran this in 05 and 06 and it worked but i thought purely due to the big-ish rad and fan (forgot the dimensions, sorry). it looked horrible but i guess it works well against latent heat.

Joy, what do you mean about mini-pods above pods. Like winglets or small bodywork??

[Mikko Ahola]

Our bodypanels used in 06 and 07 cars were designed to fit the 06 frame so that the big sidepods suplied air for the radiator at left side and for the engine air intake and intercooler at right side. The minipods were first designed to do something but that never happened on the 06 car.

Now with 07 car we used the same panels and used the right big pod for radiator cooling. The minipod at right suplies air to the engine intake and at left we have a duct to cool the ignition coils. The left big pod is just there. No real fuction.

We think that if you can figure out a way to go without the huge bodypanel stuff you so go for it. But probably we will have some kind of air guides in 08 also. We´ll see...

Chistopher:

You can see some minisidepods at the top of the big ones in the picture:

http://www.formula.stadia.fi/kuvat/06-index-kuva.jpg

[Joy Pathak]

Originally posted by Christopher Catto:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kai69i:
run your radiator at an angle of about 70 degrees in the open (no sidepod at all)
Kai

funny you say that. I thought it would have been hopeless. we ran this in 05 and 06 and it worked but i thought purely due to the big-ish rad and fan (forgot the dimensions, sorry). it looked horrible but i guess it works well against latent heat.

Joy, what do you mean about mini-pods above pods. Like winglets or small bodywork?? </div></BLOCKQUOTE>

Minipods on top of the sidepods... for intake or just aeriating engine area.... helsinki has them... and missouri had them.

[Kai69i]

funny you say that. I thought it would have been hopeless. we ran this in 05 and 06 and it worked but i thought purely due to the big-ish rad and fan (forgot the dimensions, sorry). it looked horrible but i guess it works well against latent heat.

Hi Christopher,
70 degrees does sound like a funny angle, but so does having the largest possible cross sectional area at the front of the pod (as I also mentioned). An angle such as this promotes the largest possible cross sectional area to the flow. Hence, this is also why some teams run a 'bent' radiator.

But you need to remember that a larger sidepod will also be required for packaging purposes of the heat exchanger.

These FSAE cars are certainly weird beasts!

Anyway, although as weird as it sounds, I am very confident that Ferrari would be running their radiators at an angle between 65-72 degrees in their cars. It is a nice angle even for F1 applications.

If you have access to a wind tunnel and heat bench, jump in there and you'll very rapidly see what I mean. If you don't have access to these, do some parametric optimisation in a CFD package such as Fluent which will indicate the same trends.

Cheers,

Kai

[Fyhr]

Not entirely on FSAE topic but the latest (at my local shop anyway) Racecar Engineering had a nice article on sidepod/cooling design, as well as coverage on this years FSAE/West/FS competitions. Well worth picking up if you haven't got it already

[Joy Pathak]

Originally posted by Fyhr:
Not entirely on FSAE topic but the latest (at my local shop anyway) Racecar Engineering had a nice article on sidepod/cooling design, as well as coverage on this years FSAE/West/FS competitions. Well worth picking up if you haven't got it already

What edition.....month... possibl?

[Anday]

it's the september 2007 issue. vol 17 no 09.
i just happened to have it within reach, it's some interesting stuff. some cars are featured for good reasons and others are featured for being quirky or illegal, but overall it's good stuff all around.

[rjwoods77]

The articles written by Mr.Mitchell were better in techincal content than I have seen in recent years. I think he might have gotten UWA 4 wheel steer wrong although. UB was given the nod for the most innovative car and we didnt even bring it. That is a first for them to mention a car that was never brought. They must think it is a good idea. Mmmmm....

[benny41]

it would be nice if us aussies could get it early than 2mths behind.

[TG]

Originally posted by benny41:
it would be nice if us aussies could get it early than 2mths behind.

Damn, that sucks. I'm in the western part of the US and I already received the October issue at the beginning of this past weekend. If you get the magazine regularly, try writing the publisher to see if you can get a discount on a subscription with first class mailing.

[benny41]

[/QUOTE]

Damn, that sucks. I'm in the western part of the US and I already received the October issue at the beginning of this past weekend. If you get the magazine regularly, try writing the publisher to see if you can get a discount on a subscription with first class mailing.[/QUOTE]

See the thing is i work in a newsagent and i can get it significantlly cheaper. as the aussie ppl no it cost around 17 bucks oh well ill just read about the FSAE/West/FS competitions in december. lol

[sscollins]

We are aware of the Aussie problem... we have a similar problem in the USA. We are working on it...

I have heard talk of a really really big student discount for the digital edition (far bigger than anything I have seen before). Not sure if/when it will happen.

[Erich Ohlde]

www.zinio.com (http://www.zinio.com) its electronic and you get the issues the day they are out. only like 70$ for a subscription. plus you can get old issues as well

[Hi-oct]

I am the car body designer of a new fsae team. I would like to know what exactly is a sidepod. Initially I thought that the sidepods are those that channel air into the radiators just plainly without any ducting provided. However now I find that this is wrong and that sidepod is just a shroud for purpose external aerodynamics and aesthetics. Moreover a separate ducting inside the sidepod is required to channel the air with the help of diffusor to create pressure and decrease speed to provide best efficiency across the radiator.
I would like to get a clear description of whats a sidepod and what is to be inside it (ducting or any other components). Also about the materials commonly used for ducting .

[AndrewTC]

A sidepod is an external piece of bodywork that covers one side of the car. Many teams use an internal duct inside the sidepod to assist with cooling. However, the sidepod can be designed to work as a duct itself and therefore the internal duct is made unnecessary.

The most common setup is to use two sidepods on each side, one to cover the radiator and the other to cover the exhaust. This explains why many teams do not integrate the sidepod and duct into one part if they wish to use symmetrical covers. Often they are made from fiberglass or carbon.

[MCoach]

Originally posted by AndrewTC:
A sidepod is an external piece of bodywork that covers one side of the car. Many teams use an internal duct inside the sidepod to assist with cooling. However, the sidepod can be designed to work as a duct itself and therefore the internal duct is made unnecessary.

The most common setup is to use two sidepods on each side, one to cover the radiator and the other to cover the exhaust. This explains why many teams do not integrate the sidepod and duct into one part if they wish to use symmetrical covers. Often they are made from fiberglass or carbon.


Aluminum is still a very fond choice for many teams.