A quiz for people

[AeroMcAeroFace]

Well it did say that the suspension was very soft, and if we assume that the car is actually a wing shape (which it isn't) and it only increases angle of attack a few degrees it isn't impossible to have an increase in lift with virtually no increase in drag.


CLARK Y AIRFOIL (clarky-il)

[aerohead]

I'll guess, all of the above.

[freebeard]

Yay! Someone agrees with me. Sorta...

[aerohead]

Originally Posted by JulianEdgar

I haven't been able to find a pic but I assume it's fairly flat.

Years ago I found an article online from Elsevier, which covered all the HONDA Dream solar cars,including some which never raced, with 3-views each I think.

[kach22i]

Late to the party, I would have guessed lift.

Question is, is too much lift what ever makes the driver white knuckle it and pray to God?

Or is too much lift an actual measurement with corresponding ratio to weight and speed?

I am not a professional sports car driver right at the edge of disaster every lap.

I just wanted my old truck to feel planted at speed leading to less stress, hence the anti-lift devices and treatments.

Good example this Honda solar car is, lift has been a taboo topic in this forum for too long.

Safety first was the motto of a company my father worked at, it was on all the pencils I used as a child. I think it sunk in.

[aerohead]

Originally Posted by JulianEdgar

Here is the second part of the answer:



So what happens when there is a yaw (crosswind) component to the airflow? Not good things!

The CLf (yellow diamonds) doesn't change much - in fact, it actually improves (gets lower).

But the CLr (black diamonds) increases massively, going positive (into lift) at only about 4-5 degrees of yaw, and then reaching a stunning 0.53 at 15 degrees of yaw. That's the highest CLr I've ever seen.

As a result of that, the overall CL (red squares) goes to well over 0.6(!!) at 15 degrees yaw.

Frontal area of the car was 0.999 square metres and mass was 330kg - I'll let someone else do the maths for the effective weight of the car at 60 km/h - let alone at 15 degrees of yaw and 140 km/h (obviously, in those conditions the car would have been impossible to drive).

So, next time you read someone saying confidently that, well of course, streamlined cars have low lift, you can say: "You're dreaming!".

I'd just want to mention that the Dream is not a 'streamline half-body', something quite different.
The 2013, Cambridge University Eco Racer ,CUER , would be more of an example of a half-body.

[freebeard]

Originally Posted by kach22i

Good example this Honda solar car is, lift has been a taboo topic in this forum for too long.

I tried. Not the hill I wanted to die on.



duckduckgo.com/?q=jocko%20johnson%20triple%20nickel

[aerohead]

Originally Posted by kach22i

Late to the party, I would have guessed lift.

Question is, is too much lift what ever makes the driver white knuckle it and pray to God?

Or is too much lift an actual measurement with corresponding ratio to weight and speed?

I am not a professional sports car driver right at the edge of disaster every lap.

I just wanted my old truck to feel planted at speed leading to less stress, hence the anti-lift devices and treatments.

Good example this Honda solar car is, lift has been a taboo topic in this forum for too long.

Safety first was the motto of a company my father worked at, it was on all the pencils I used as a child. I think it sunk in.

If memory serves me, a condition of competing in the World Solar Challenge, is that a vehicle remain safely stable in the presence of the Australian, triple-trailer land train's turbulence and wake, of which the racers will share the road during competition.
If a body doesn't produce lift, longitudinally, it may if it manages to get sideways ( center of pressure issues ).
GM deleted the wheel fairing package on Sunraycer in 1987, due to an associated yawing moment issue for this very reason. Drag went up, from Cd 0.125, to Cd 0.143 or so. They ended up winning anyway. They did a terrific rehearsal for the campaign, providing there own weather reports, knowing when to 'hold' or go balls to the wall.

[mort]

Originally Posted by AeroMcAeroFace

Well it did say that the suspension was very soft, and if we assume that the car is actually a wing shape (which it isn't) and it only increases angle of attack a few degrees it isn't impossible to have an increase in lift with virtually no increase in drag.

You mean no increase in coefficient of drag,
-m

[AeroMcAeroFace]

Originally Posted by aerohead

I'd just want to mention that the Dream is not a 'streamline half-body', something quite different.
The 2013, Cambridge University Eco Racer ,CUER , would be more of an example of a half-body.

I am not sure if it is the same car but they did have a car crash due to "a sudden loss of dynamic stability" https://www.bbc.co.uk/news/uk-englan...shire-41486526

But seeing as their steering committee doesn't seem to understand aerodynamics at all “A bicycle has one human-horse power (300W), and Mirage has just four [sic] human-horsepowers" "However, my road car needs 1,500 human-horse [sic] powers to get me from A to B" https://www.cambridge-news.co.uk/new...-made-13549820

Yes, I do know that that a steering committee doesn't actually deal with car steering but what sort of road car needs 1500 horsepower?