Renault R31

[mep]

lightweight=> The tiny amount of fluid (MERCURY) required would be lighter than an equivalent spinning mass

Small weight and CofG=> As Inerters tend to be mounted relatively high a weight saving will aid CofG height

No, I disagree there.
1.You actually need mass. Thats how that thing works. So they probably have the same weight.

2.Mercury has higher density as steel. So it is heavier

The advantage is that it has less friction.
It doesn't wear and is more reliably.
Also it is just much more easy to build.

[aleksandergreat]

lightweight=> The tiny amount of fluid (MERCURY) required would be lighter than an equivalent spinning mass

Small weight and CofG=> As Inerters tend to be mounted relatively high a weight saving will aid CofG height

No, I disagree there.
1.You actually need mass. Thats how that thing works. So they probably have the same weight.

2.Mercury has higher density as steel. So it is heavier

The advantage is that it has less friction.
It doesn't wear and is more reliably.


Also it is just much more easy to build.

No beacuse, the whole system is smaler (acording to Srabs)

[mep]

Well it can be smaller but the mass is the same.
Maybe they can save some weight with the stuff around but the actual mass you use for your damper has to be similar. Thats how physics work.

[hardingfv32]

mep

So you are proposing that the mass used by either style inerter is the same as the mass in the original mass damper which is now illegal. It does not sound unreasonable.

There is no way to cheat the physics of the situation to be able to use less mass?

Brian

[mep]

Well I say that the mechanical J-damper will have the same mass as the hydraulically one.
They are doing exactly the same thing.
Accelerating and decelerating a mass.

The tuned mass damper is a different story.
It might have a higher mass because it is linked to the chassis whereas the j-dampers are more integrated into the suspension.
Have the picture of the spring mass system in your mind.
The tuned mass damper is a mass mounted in series with the chassis mass (on top of it). The j-damper is a mass mounted in parallel with the spring and conventional damper. Therefore they can have different masses and behaviour as their position is different.

Is there a way to reduce mass?
Yes maybe you can have some kind of gearing mechanism.
This could be the helix on the shaft. However both the hydraulically and the mechanical j-damper have this helix.
So they will still be similar.
I read trough Scarbs blog now and noticed the comment about the weight.
Actually I think it is wrong.
I don't want to be impolite. Scarbs is doing a great job but I question if he fully understands the mass damper.
However we need that patent paper.
If anybody has it sent me a PM.

[timbo]

However we need that patent paper.
If anybody has it sent me a PM.

Here you go
http://www.sumobrain.com/patents/wipo/F ... 89373.html

A fluid inertia in the fluid line varies as the square of the surface area of the piston relative to the cross sectional area of the line (i.e. as the 4 th power of diameter for cylindrical lines). Thus for a piston diameter of 40 mm, and a line diameter of 4 mm, the inertance is (40/4) 4 = 10,000 times larger than the mass of the fluid in the line. Hence inertances in the range of 10 to 500 kg, which is a typical range required in Formula One racing cars, can be easily realized with only 1 to 50 g of fluid in the line.

[ringo]

After reading the patent i now see what the device is trying to achieve.
It's basically a flywheel, but instead of smoothing out combustion events of an engine, it smooths out disturbances transmitted through the suspension.

The thing with it though, is that it only smooths forces via the pushrod, bellcrank, and heave shaft/terminal. Therefore it is limited to only forces on the car or at the wheels that translate the push rods.
Unlike a vibration absorber that doesn't need to mechanically linked to the car's body. The VA needs only be in contact with the body of the car, and only cancels vibrations withing a certain frequency range.
This is why i was figuring that the bump stop was the "inerter", but my understanding wasn't clear between that and a vibration absorber.

I wonder how noticeable the smoothing and resisting of force is with the inerter?
It seems to me it's primary use is to make haphazard and fluctuating real world forces on the wheels more like man made force models, with defined funcions, by smoothing.

It's a really interesting device. It could also be used in the front wings, come to think of it. It could solve ferrari's fluttering problems.

[hollus]

This device is also relevant to the real world outside F1. Rarely seen these days.

[Pierce89]

After reading the patent i now see what the device is trying to achieve.
It's basically a flywheel, but instead of smoothing out combustion events of an engine, it smooths out disturbances transmitted through the suspension.

The thing with it though, is that it only smooths forces via the pushrod, bellcrank, and heave shaft/terminal. Therefore it is limited to only forces on the car or at the wheels that translate the push rods.
Unlike a vibration absorber that doesn't need to mechanically linked to the car's body. The VA needs only be in contact with the body of the car, and only cancels vibrations withing a certain frequency range.
This is why i was figuring that the bump stop was the "inerter", but my understanding wasn't clear between that and a vibration absorber.

I wonder how noticeable the smoothing and resisting of force is with the inerter?
It seems to me it's primary use is to make haphazard and fluctuating real world forces on the wheels more like man made force models, with defined funcions, by smoothing.

It's a really interesting device. It could also be used in the front wings, come to think of it. It could solve ferrari's fluttering problems.

What you keep calling a vibration absorber is the same thing as the tuned mass damper Renault used in 06 till it was outlawed.

[ringo]

Well when the inerter was being called a damper, that was the whole confusion wasn't it?
It has damping effects, but it's not a damper.

A tuned mass damper is a vibration absorber, but what Renault used in 2006 is not clear to me. The media articles have't been very sure on this.
Were they using an inerter, similar to mclaren or a vibration absorber?
Someone please make this clear.

You see for F1 technical, we need to cut through all the verbal gymnastics and get to the point.
It doesn't take one thousand words to describe an inerter as mechanical capacitor.

[shelly]

The inerter is very old stuff (2004 maybe?). The interesting part is the liquid metal addition

[mep]

The thing Renault used 2006 was a mass attached with a spring to the chassis.
So in principal it is mounted in series to the other masses.

Mclarens j-damper is a mass mounted in parallel to the spring and damper.
Renaults hydraulicall j-damper is the same.

You notice there is a general difference between the two concepts.
However both are (probably) able to improve responses for 1 given frequency which can't be tuned with the classical damper because of the given tire stiffness.

[ringo]

You seem to be as confused as me.
After reading the patent and about the "J Damper", it can be said that Mclaren's J damper is not a damper. The word damper was used to mislead.
And most of the F1 fans have been mislead, so you cannot be blamed for that.

Mclaren's J damper was more than likely a fly wheel based inerter, rotating mass.

Renaults 2006 system was more than likely a rotating mass inerter and not a tuned vibration absorber correct?

So in essence both teams were using inerters and not vibration absorbers am i right?

There is no different between the device for the 2 teams then.
I think everyone is lost as i was at the beginning of the discussion. I now realize what both concepts are and i think we should all adjust our perceptions.

I am assuming neither team have used a vibration absorber. They both have used inerters.
When i get the energy i'll do a simple example of a vibration absorber and what its purpose is. Then i'll try the inerter using a flywheel type example, as i'm not too familar with it yet. I hope i can do this! Lazyiness i tell you.

[Jersey Tom]

Think we need to be more careful about the word "absorb" vs "dissipate" in these discussions.

[timbo]

Renaults 2006 system was more than likely a rotating mass inerter and not a tuned vibration absorber correct?

No. It was exactly that -- a weight on a spring.