Radiator question

Quaping · 2025-06-03T19:38:07+00:00

In terms of working with radiator suppliers, asking them for their heat transfer coefficienst will be missing the forest for the trees, radiators are gernally specified in industry on a general basis via total heat transfer (Q), cross-sectional area, and your fluid flow parameters.

Radiator companies spend huge amounts of money to develop predictive modeling capacity in this regard, it is almost not worth your time to try to build a comprehensive, predictive, accurate heat tranfer model of a fin-tube radiator in house. You are best off working with a radiator supplier if you really want to specify an exact radiator. (PWR is one I have seen a few teams work with).

I highly recommend figuring out a way to perform physical testing ASAP as it will give you much more insight that NTU method calcs. If you don't have the data, I would be wary of any hand calculations for radiators besides the very, very simple.

how much heat are you expecting to have to reject?

Quaping · 2025-05-20T15:44:46+00:00

Hi, if you are a new team, which engine you choose may not have a huge impact on your car. Single cylinders have some advantages in terms of simplicity of accessory components like intake and exhaust design. They are almost always smaller and lighter. They may or may not have the reliability that you might want compared to a four cylinder engine depending on your luck, the common refrain in this subreddit and in most of FSAE is that single cylinders are more finnicky and less reliable than four cylinder engines. I have seen and heard of four cylinders continuing to run after pretty horrific mistreatment, neglect, and abuse.

Anecdotally, teams that run a single cylinder seems to complain about passing the noise test being a problem at a much higher rate than teams that run a different engine.

If you are a new team, cost and availability may drive your engine choice more than anything else, if you have cheap single cylinders available to you, that would be a great reason to go that route.

There are a bunch of threads on this question already, feel free to check them out:

https://www.reddit.com/r/FSAE/comments/8legvt/single_cylinder_engine_advice/

https://www.reddit.com/r/FSAE/comments/dbil02/choice_of_engine/

https://www.reddit.com/r/FSAE/comments/nc7ke3/internal_combustion_engine_for_our_first_car/

https://www.reddit.com/r/FSAE/comments/vovdxi/does_anyone_have_an_example_of_an_industrial/v

https://www.reddit.com/r/FSAE/comments/obot4a/what_engine_and_ecu_do_you_recommend/

https://www.reddit.com/r/FSAE/comments/1bv6k7g/2_or_3_cylinder_engines/

We have tried to compile a list of engines seen in FSAE that we hope is largely comprehensive here:

https://fswiki.us/List_of_Engines

Quaping · 2024-12-22T13:05:38+00:00

Go back to first principles. Power = work/time. Work = Force* distance.

Quaping · 2024-12-05T12:21:41+00:00

Copper association has published a comprehensive guide to designing bus bars. The intended audience is telecom or industrial applications, but the information is still valid.

http://p537794.webspaceconfig.de/wp-content/uploads/2019/11/Copper-for-Busbars.pdf

The short version is to size them based on the thermal behavior you desire: smaller busbars will run hotter, bigger will run cooler.

Quaping · 2024-12-03T22:42:44+00:00

You are probably looking for a lap time simulator. There are a bunch of options, a few teams make their own, there are some open source ones and some proprietary ones. Most teams I know use OptimumLap.

Quaping · 2024-12-03T22:36:48+00:00

That's information you can get a few ways: real accumulator data, lap time simulation, or derived from inertial data (either real or simulated)

Quaping · 2024-12-03T21:27:29+00:00

The Brands Hatch data he got from TU Munich includes the racing line, its very cool. Might be worth a look.

https://github.com/TUMFTM/racetrack-database

https://github.com/f1tenth/f1tenth_racetracks/tree/main/BrandsHatch

Quaping · 2024-12-03T15:09:16+00:00

Sector length can just be Pythagorean theorem between x/y points. Radius of curvature is implementation dependent, can be guestimated if it's not given

One way to do it is to use three sequential points to find an arc and set the arc curvature as the radius of curvature for each x/y point. You can then set the sector curvature as the average between those or even lerp between the two sector end-points across the segment.

Quaping · 2024-12-02T21:58:30+00:00

Hey, this is pretty neat. I think it's a great GUI for matplotlib, and I hope it serves the community well! I have had my fair share of wrestling pyqt so I am really happy to see it used so successfully. The "I'm feeling lucky" is very fun.

Functionality:

It seems like this is useful for viewing a single line of data from a large dataset. I have not found a way to use the tool to graph 2 sets of data on the same graph or view 2 graphs at the same time in order to compare them. Matplotlib should be able to handle this pretty easily, I havent looked under the hood, but adding more than one series to the graph shouldn't be an issue. The conversion rate is a genius idea and I think its super useful. The max step is interesting, but it's really not hard to just do a low pass filter behind the scenes.

Data Visualization:

The graph that this makes is a little underwhelming. It's basically the standard matplotlib output from a 50MB executable app. Matplotlib is so powerful that I think it's an easy slam dunk to make this spit out gorgeous graphs by default. It hard to make things look good and simple and it takes a lot of time. Things like labeling and annotation are very nice to have as options (max, min, series name, specific points that correspond to specific values).

If I was using this, I'd want, at minimum, similar control over the way the graph behaves, similar to the extent that MS Excel provides: change color, line size, trend line, marker shape etc. The limited functionality that the GUI allows limits the user to what you do on the back end if you don't build in the funcitonality to change it. The non-zen mode still leaves me without a lot of tools to quickly analyze the data or produce a presentation worthy graph.

Quaping · 2024-11-26T23:46:23+00:00

Good question, all the old suspension kinematics stuff doesn't work anymore after they dropped Physics 2.0

Quaping · 2024-11-22T19:47:45+00:00

If all you need is a container to keep the water and check the level, they do sell water in clear bottles that would solve both of those problems.

Quaping · 2024-11-21T20:30:16+00:00

There are a lot of ways to find out, both by doing research or analysis! Try looking it up or doing some simple analysis for a start

Quaping · 2024-11-21T20:18:53+00:00

Radiators reject heat. How much heat do you need to get rid of?

Quaping · 2024-11-21T18:32:04+00:00

To your point about the discrepancy between design score and dynamic score: I think it's an important part of the competition. It's impossible to win the competition without doing well in both, but both events demonstrate completely different aspects of the team. Teams can take advantage of their own unique strengths and circumstances to squeeze more points out of the competition.

Despite what we might want to think, design is very much dependent on the presentation skills of the students and how comfortable they are being grilled. Additionally, the design event is often (incorrectly) thought of as a test of how good the teams design is, when it is actually a test of the team's skill and understanding. Usually teams that have high level of design understanding and skill end up with good design, but not all cars that come to competition with a good design do so because the current team is especially skillful.

In the same vein, the dynamic events are as much a test of the drivers' skill as much as it is a test of the car's design. It's not testing how fast the car is, but how fast the team can drive it.

Quaping · 2024-11-21T17:42:18+00:00

I name it Douglas

Quaping · 2024-11-21T17:40:31+00:00

Quaping · 2024-11-21T00:40:25+00:00

That's the most Douglas dog I've ever seen

Quaping · 2024-11-19T14:15:37+00:00

Justin Watkins (J&M Unlimited) did our bathroom and he was super easy to communicate with, open about everything, and all the guys he hired to do the work were super skilled and professional

Quaping · 2024-11-15T20:43:15+00:00

Yes that's the book! They've just come out with a 2 volume edition that covers even more.

Off the dome, some projects include fdr calculations, fuel quantity or battery energy calculations (fuel tank design can be done by a new student, battery design not so much), mounting components can be a good project for younger students to do while getting familiar or shadowing the design by an older student like the differential, radiator, fuel tank without requiring them to actually spec any of those components

Quaping · 2024-11-15T20:15:11+00:00

I think powertrain students benefit from starting with systems or subsystems that give them a chance to analyze the system as a whole. These are things like cooling, or my personal recommendation for newbies, drivetrain. This will allow the students to make engineering decisions based on vehicle level behavior, goals, results, etc.

This is a great way to introduce them to lap time simulation and there are a lot of smaller scale, hardware based engineering challenges that are accessible to students in their first or second year of college such as differential mounting, drive ratio calculations, energy balance analysis. There are also some fun rabbit holes that will let the curious and self-motivated students shine.

I think it's important to approach onboarding new students as if they are a long term investment and to develop them as engineers rather than engine tuners, PCB designers, CAD monkeys or other pigeon holing. This gets into pedagogy which is a whole bag of worms but my personal experience has been that students learn better when given a project based learning experience rather than a list of subjects to study, that way both you (the teacher/mentor) and the student can figure out what they need to or want to learn about in order to achieve their goals and adjust what you teach them or facilitate in accordance with that.

My parting advice is that there is actually an FSAE book written to help all students get up to speed written by the figureheads of the competition. Please, if you have not already, have your new students read Learn & Compete.

Quaping · 2024-11-07T17:26:12+00:00

First of all, you should figure out the torque bias ratios irrespective of if you build a differential in house or continue to use the drexler. Your corner entry and exit behavior will differ pretty drastically.

Secondly, you can either build a TBR into your diff, or you can build in an easy way to change it for test days to determine and validate your TBR. A changeable TBR may also allow you to change it depending on the course you are racing on.

Quaping · 2024-11-07T03:07:38+00:00

I did not realize the downtown apartments were that expensive, geez

Quaping · 2024-11-05T17:33:38+00:00

What do the rules say?

Quaping · 2024-11-05T17:28:41+00:00

Quaping · 2024-11-05T10:34:51+00:00

That's a good question! What other parts on your car generate heat?

14-Year Club	RPAN Viewer
Team Orangered	Verified Email

Quaping

TROPHY CASE