Engineering Explained I'm curious as to your opinion on this. Even though radiators are a relatively small portion of the weight of a car, by my logic, this puts a lot more weight in the pods. With a 20x20x10 radiator, you've got 400x of weight (x being average weight per cubic cm of the radiator including coolant). If you go to your rather extreme example of 60 degrees, that then becomes 16,000x, given the same weight per cubic cm. That's a 4 times heavier radiator for potentially minute power gains. I'm not saying that this wouldn't work (If it didn't, I'm sure it wouldn't have been used in F1), but I'm not convinced of a net gain in performance. Am I missing something, or is this just one of those things that you have to fine tune and play with?
Soh-Cah-Toa!!! I haven't heard anyone else use that method since my trig teacher taught it to us ages ago. Glad to see it's still being used. Well done on your videos...
good video, the only question I have is - when the rad is straight up the fins offer the less resistance, but when its laying over the fins will act as a resistant fan. the side positioning is therefore the best, the the air still has to change direction
The amount of heat that you can remove from the radiator increases, since you are spreading it out more. If you don't remove the full potential of the radiator with a single flat area (it's tempt. continues to go up) by spreading out the fluid you can dissipate more heat. Size of the radiator is important as well as how much air passes through it.
your videos are bad ass dude! i love motorsports and the engineering behind it!! id like to be an engineer some day and your videos are really easy to follow haha
Fantastic lesson Mr EngineEx:) one of the most enjoyable instructional cid's I've seen yet. If my mathematic's teacher taught me using these type's of formula example's I would have been a much keener pupil, not to mention smarter too;) Great stuff!!!
I did like the rubber band. Its worth noting the drawback to this system is depending how the air travels through the heat exchange the velocity will drop (if the air turns to go perpendicular to the ht x face) or the effective depth will increase (if the air travels straight and flows at an angle to the face). either of these effects will reduce the advantage of the larger face area.
So are you tilting the base 20cm radiator forwards or backwards? I was just wondering if a similar aspect could be used with a daily driven street car.
I didn't take any kind of advanced math in school. So I don't fully understand the math. But I do understand what you're saying about changing the shape and still keeping it the same frontal area. Looking directly into it, it would still look like a 20x20 square. It's not until you look at it from different angles that you actually see the real size of it
Think of it using the air conditioning principle when the air is compressed it heats up when it decompresses it cools. As you make the air compress into a radiator with fins that block half the air flow then it must compress to allow the air to pass. This process heats the air and slows the air passing threw. Angling the the radiator to increase its surface area also reduces(or reverses) compression in the same airflow needs to pass the "obstruction" especially in the air ramming scenario in F1.
Looking at doing something similar and this video came up. If you angle that back though the fins will also be angled back and at some point it seems like air would flow over the fins instead of through them. Unless the fins are designed at 90 degrees to the ground despite the radiator being set back say 45 degrees. You could redirect that air flow to then flow at say 45 degrees matching the fins. But then your creating turbulence and/or adding weight and/or loosing efficiency in part of that radiator
It is correct that you aren't affecting the frontal area, however, there are also aerodynamic variables to consider with the design of the radiator that will affect the drag induced by the heat exchanger. The most basic thing to consider is how many fins per square inch the radiator uses in the core. Next is the angle of those fins, and/or if they are louvered. All of these will affect how much drag the radiator induces on the car.
Basically you're increasing the volume of the radiator, without making it thicker (the distance the air passes through) yet preserving the frontal area. So the internal surface area of the fins is greater.
So what it seems like; Its like stretching the radiator for more air surface contact but you would tilt it so that its overall height would be the same as if it was the unstretched version. But wondering if the fins angled or not. If not, it would see to put some down force or strain on the fins kinda creating a bunch of tiny spoilers assuming the top is pushed toward the front and the bottom pushed towards the bad of the car.
One thing I don't get.. The surface area increases if you tilt it but since the air still comes directly from the front you will get just as much air through the radiator whether its vertical or tilted so what do you gain by tilting it?
I believe this concept reduces drag even while maintaining the same frontal surface area. The reason being that the shape has changed to become more aerodynamic. Drag is a function of shape as well as frontal area for a given fluid and velocity. That given, by tilting the radiator back you do loose some efficiency, due to the fact that the pressure delta across the radiator is reduced. Great post!
So if you get a 1m^2(100cm*100cm=10,000cm^2) piece of paper and draw 1cm thick lines down the paper with 1cm gaps you get 5,000cm^2 of fins(inked area) and 5,000cm^2 (blank area), the fins are blocking half the frontal area. You do the 45degree trick and you now have a 1.9881m^2(141cm*141cm) piece of paper. Repeat the lines and you have 9,940.5cm^2 of fins and 9,940.5cm^2 of air passages, almost no air "blockages" in comparison to its frontal area. So you can maximise airflow to match your frontal area and maximise the fin area at the same time. So there is a maximum gain for each level of fin density.
Okay, so, increasing the angle of the radiator will increase its radiant surface, but at which point this will make it a disadvantage? I mean, if the angle tends to 179°, it would have a very very very long length before it reaches a 20cm height, almost as much as infinite, and if the angle tends to 180° the length would be definetly infinite and thus wouldn't have any active radiant surface. so, which is the exact limit angle? I'm sorry for my really really bad english but i'm italian!
Air will be moving at the same speed, but more air will be passing through the radiator (in volume) at any given point in time. (The volume of the radiator is larger).
I think if you section the area throughout the air intake's length, each section has a 20X20 area, but on each cross section a certain amount of area of the air goes through the angled radiator. Add up the area cooled by the air for each section and you will find that the total air cooled area is bigger than if the radiator was one 20X20 section
EngineeringExplained, please consider making tutorials on calc, physics, and chemistry!! it would be a great edition to your car videos! to know the fundamentals of cars, one must know chemistry, math, and physics right? ; - )
Thats awesome, so they could improve road car cooling buy using angled radiators, or maintain the same cooling by using smaller radiators in this way thereby saving money. Presumably the fins of the radiator need to be angled in the same orientation in order to maximise the effect?
Perhaps the complexity of manufacturing. It all goes in to cost, and is it worth the difference? But a new idea is always welcome, perhaps there is a better way!
I'm having a hard time trying to explain what I'm saying without a visual aid. Don't think of the air as coming in a square shape. For example let's say this "I" is a radiator, and so is this "\" (The shape). Now when air comes at the flat radiator "I" it looks like this IIIII -> I. (Here, IIIII is the sheets of air about to pass through). But the air that is flowing through the slanted radiator would look more like this \\\\ -> \. Now do you see how you're heating different portions of air?
Yep, it's tough trying to find methods that everyone would be interested in though. Teaching is a difficult thing to do, considering you have to bring a large group of different backgrounds to reach a similar conclusion.
"increasing the surface area of the rad, w/o increasing the frontal surface area of the car" . But you're not taking into account the reduced efficiency of not getting direct air-flow
Great video. I really love your channel it's so helpful :D I have a question if you wouldn't mind. Does it make any difference if the radiator is tilted forward or backwards? which is better and why? And if you could provide me with a source where i can read about it I'd be very grateful :D
a radiator is a block consisting a lot of thin pipes, so if we want to maximize the surface area we have to use more pipes, and the air gap will be smaller between(more drag), but from this point of view its the same area if its tilted or not, the only difference is that the bottommost and topmost places are not sending sending directly their heat from top to bottom and i can see there beter effect, but far less, than the described 2ratio
1: Wouldn't matter. It's just a diffrent system for the same problem. You would get the exact same result. You can easily divert degrees into radians and back. 2: You will facing a problem. In a F1 car, you haven't much space for the radiators. If you angel the radiator, you need more free space because the overall lenght of the radiator is increasing. Also, if you look at the cosinus-function, they get nearly linear after 45° (1/4 pi). So, i would say, more than 60° makes not much sense.
There has to be some trade-off, given that less air is going through the radiator when it is tilted, right? You can't tilt it 90 degrees and have lots of surface area with zero frontal area, because you won't get any cooling. There's probably a "sweet spot" angle that has the best balance of surface area vs air going through to maximize cooling.
Random thought: Wouldn't it be better for the bottom of the radiator be placed closer to the front of the car than the top of the radiator? Opposite to what you have drawn on the white board. Wouldn't this help provide more downforce, as oppose to lift? Or does it have to do something with not allowing the hot air to get trapped towards the top of the radiator at idle?
You have to take into consideration that the first thing you explained in the beginning starts to happen when you tilt it enough, the depth of the radiator increases. So its not that big of gains in reality that you stated. Also i think the aerodynamics change a little with tilted vs not tilted, tilted doesnt get the air "rammed" thru like in the non tilted? All just my common sense tingling so might be wrong! Maybe make these kind of radiators IRL and test in and out temperatures?
I don't think cooling is working in this theory? Frontal area equation should be addressed to the direction toward to the wind. Now the radiator is tilted it might face the other direction which would cause more drag, or it might face the right wind direction but one corner sticks out the most will start to cool down then the far behind corner will be cooled the last. I think it's just matter of which corner get cooled first and not actually increasing the cooling surface area by tilting for better cooling performance.
Take a cup of boiling water and pour it onto a 20X20 section of room temperature concrete and measure the temp of the water, then take that same cup of water and pour it on a 28X28 section of room temperature concrete and measure the temp of the water. It takes more energy to heat a bigger surface area, simple as that, so long as the engine doesn't get larger, or run hotter to compensate, the volume of air staying the same will have no effect.
Great video, but I have a general question about F1. Isn't the whole point to have the least amount of drag possible on the car to make it have a faster top speed and acceleration? Is there ways they make the radiator have less drag, but still cool the car effectively?
I understand what you said about the geometry, but doesn't the air flow rate remain constant and each bit of air goes through the same distance inside the radiator? To put it another way, doesn't the internal surface area(the surface area of fins inside the radiator) remain constant? Since the fins must be parallel to the direction of travel.
@Engineering Explained, Is tilting premanufactured cooling cores like a radiator or intercooler from aftermarket suppliers - typically seen in a v-mount setup - even worth the effort. DTM and GT cars also use typical cores, and the fins would not be skewed increasing surface area. I can only assume a bespoke built as you described by a F1 manufacturer tossing almost limitless funds would benefit? My interest stems from initially reducing charge piping volume and reviewing orientation for a v-mount setup on my A80, but it all seems to be more trouble than it's worth even for a autocross/track car if the surface area does not change and only the angle...
this video is a little bit misleading. it's ignoring the fact that you will not have more, but same volume of air going slower(!) over bigger radiator!
I think I understand what you mean, but I don't get why should it be better. The airflow is the same. The cross-section area (and mass) of air passing through the radiator limits the amount of energy it can take away, no matter what shape of radiator is. The only matters cross-section area of radiator, doesn't it? It's fact that they have radiators more like "\" then like "|". But what are advantages of such solution? I am sorry for asking the same question.. :( but I really want to figure out.
Given that I never understood maths in secondary school, and still don't understand it now, what I got from this video is that F1 teams tilt their radiators. That should be the gist of it, right?
i was wondering the same thing. The area*speed of the air that is going inside de carburator is always the same.. so the amount of heat it can absorb is limited to this number. i`m wrong? I loved your videos. PD: Sorry for the english.. not my first language
how about productivity? Angle means more scrap at the same time. also how much space do you think you have in a car for radiator? I dont even want to mention about efficiency.
