Harmonic dampener heat

[BOOT]

I've read in the past that elastomer dampeners create heat from a few diff sources, ie like TCI rattlers description. I kinda wondered how much actually not too long ago, then just saw this article today http://www.enginelabs.com/news/engine-h ... n-to-heat/

An argument could be made that it doesn't matter to a moving vehicle, but if it creates heat it can not absorb or dissipate the engines heat. drag it wouldn't really matter but maybe for other types of racing.

Thoughts?

[Stef]

Both viscous and elastomer dampers generate heat when they are working from the shearing action of the silicone fluid/rubber. This is from the internal strains in the shearing medium similar to bending a piece of steel strip backwards and forwards really fast, the bend will begin to get hot. If the silicone fluid or rubber gets too hot they degrade and the damper will no longer operate properly. For the rubber damper, its heat capacity is generally dependent on damper size, rubber compound and rubber volume. It can be kept cooler by using ducting or by designing the damper to aid cooling of the rubber e.g. cooling fins/vanes. Fluid dampers on very high output engines often have vanes or fins on their casing.
For endurance or road racing bigger is generally better. Drag race can get away with smaller dampers mostly as they run quickly through the torsionals.

[pamotorman]

Both viscous and elastomer dampers generate heat when they are working from the shearing action of the silicone fluid/rubber. This is from the internal strains in the shearing medium similar to bending a piece of steel strip backwards and forwards really fast, the bend will begin to get hot. If the silicone fluid or rubber gets too hot they degrade and the damper will no longer operate properly. For the rubber damper, its heat capacity is generally dependent on damper size, rubber compound and rubber volume. It can be kept cooler by using ducting or by designing the damper to aid cooling of the rubber e.g. cooling fins/vanes. Fluid dampers on very high output engines often have vanes or fins on their casing.
For endurance or road racing bigger is generally better. Drag race can get away with smaller dampers mostly as they run quickly through the torsionals.

some special hi perf small block chevy dampers had fins on the back side.

[MadBill]

Both viscous and elastomer dampers generate heat when they are working from the shearing action of the silicone fluid/rubber. This is from the internal strains in the shearing medium similar to bending a piece of steel strip backwards and forwards really fast, the bend will begin to get hot....

So a Rattler™ pendulum-style balancer should run cooler, make fractionally more power and last forever, since the inertia forces are shuttled back and forth between the slugs and the main body, rather than being dissipated as heat.. Bonus: the degree marks can't 'creep' as the elastomer fails.

[statsystems]

Both viscous and elastomer dampers generate heat when they are working from the shearing action of the silicone fluid/rubber. This is from the internal strains in the shearing medium similar to bending a piece of steel strip backwards and forwards really fast, the bend will begin to get hot....

So a Rattler™ pendulum-style balancer should run cooler, make fractionally more power and last forever, since the inertia forces are shuttled back and forth between the slugs and the main body, rather than being dissipated as heat.. Bonus: the degree marks can't 'creep' as the elastomer fails.

Isnt the amount of heat relative to the input of harmonics?

In other words, wouldn't all the damper have the same heat output if the harmonics were the same?

Of course, once something gets to the point heat saturation, how well it gets back to normal is a different consideration.

[BOOT]

Both viscous and elastomer dampers generate heat when they are working from the shearing action of the silicone fluid/rubber. This is from the internal strains in the shearing medium similar to bending a piece of steel strip backwards and forwards really fast, the bend will begin to get hot. If the silicone fluid or rubber gets too hot they degrade and the damper will no longer operate properly. For the rubber damper, its heat capacity is generally dependent on damper size, rubber compound and rubber volume. It can be kept cooler by using ducting or by designing the damper to aid cooling of the rubber e.g. cooling fins/vanes. Fluid dampers on very high output engines often have vanes or fins on their casing.
For endurance or road racing bigger is generally better. Drag race can get away with smaller dampers mostly as they run quickly through the torsionals.

Interesting so if my damper fails I should try a larger one.

[BOOT]

I wonder if you could check/monitor damper temps on say an ATI or other elastomer type to see if it's about to fail? I would assume heat could increase as it degrades.

[MadBill]

Both viscous and elastomer dampers generate heat when they are working from the shearing action of the silicone fluid/rubber. This is from the internal strains in the shearing medium similar to bending a piece of steel strip backwards and forwards really fast, the bend will begin to get hot....

So a Rattler™ pendulum-style balancer should run cooler, make fractionally more power and last forever, since the inertia forces are shuttled back and forth between the slugs and the main body, rather than being dissipated as heat.. Bonus: the degree marks can't 'creep' as the elastomer fails.

Isnt the amount of heat relative to the input of harmonics?

In other words, wouldn't all the damper have the same heat output if the harmonics were the same?...

No, an elastomer or fluid damper turns the torsional vibration energy into heat, but a 'pendulum' damper works like its namesake. At the top of its swing, a pendulum has a certain amount of potential energy by reason of its position further from the center of the earth (or the crankshaft) than at the center point of the swing. As it moves down through the first half of its arc, it is changing potential energy into kinetic energy, which maxes out at the center. Then as it rises up through the other half of its arc the form of energy is changing back to potential and so on, back and forth, so no appreciable percentage is dissipated as heat.

[MadBill]

I wonder if you could check/monitor damper temps on say an ATI or other elastomer type to see if it's about to fail? I would assume heat could increase as it degrades.

Actually, as an elastomer or fluid damper started to fail it would become less effective and so would dissipate less energy and run marginally cooler.

[peejay]

But if it's running cooler, then less energy is being dissipated by it, so the engine is making more power?

I better stop going down that line of thought, it never ends well

[MadBill]

The energy's being absorbed instead by twisting the crank back and forth like bending a paperclip and that's not a good thing.

[Ken_Parkman]

I think the pendulum style is better for tuning to the exciting order rather than the frequency. This is a good paper:

http://www.bhjdynamics.com/index.php?ma ... 2o1dljafu1

[Stef]

Both viscous and elastomer dampers generate heat when they are working from the shearing action of the silicone fluid/rubber. This is from the internal strains in the shearing medium similar to bending a piece of steel strip backwards and forwards really fast, the bend will begin to get hot....

So a Rattler™ pendulum-style balancer should run cooler, make fractionally more power and last forever, since the inertia forces are shuttled back and forth between the slugs and the main body, rather than being dissipated as heat.. Bonus: the degree marks can't 'creep' as the elastomer fails.

They certainly do run cooler. Whether they make more power is dependent on if you can get a Rattler absorber of the right size in the available space. Over here they are called Roll-form absorbers and have been in use since the 1930's attached to flywheels, crank counterweights and pulleys. Mainly on aero and diesel engines.

[Paul Rig]

wonder if these rattlers are similar to what Ive seen used on truck tyres here in Australia.
One of the tyre shops here throws a 2-3 cups of rubber balls in the tyre to balance the tyres.
I asked him about it he said it balances the tyres on the rim and they set in place after a long run. He also said it was popular in mining as well.
We are talking 42t highway truck.