Off Topic: Fluid Power

This is off topic but I thought someone on this board would know. Where can I find a velocity curve (graph) for linseed oil and power steering fluid? This is extra credit for a school assignment.

Thanks

Do you perhaps mean a "viscosity" curve? I would suggest going to a supplier of these fluids for this data, or looking in a pump handbook.

Maybe the velocity profile?

Doh!

Yes, I meant viscosity. I thought maybe someone would have the info readily available. Thanks

Viscosity varies with a number of things like temperature and pressure. In order for someone to produce a "curve" or graph for you, we'd need to know what the X-axis of the plot is - that is, do you want a plot of viscosity vs. temperature, vs. pressure, vs. ?

-Alex

Of linseed oil?

What is that used for?

All I know about linseed oil is that it's in the paint section at Home Depot...

A quick search brought this:

"Flax is a plant from which the fibrous stems are used to make linen cloth (Irish linen was/is particularly fine) and the seed is crushed to make linseed oil. Linseed oil is used for multiple things, including feeding people and animals and applying to wooden cricket bats so they don't dry out and crack,etc. After the pure oil has been expressed the remaining mass is compressed into 'cakes' and used to feed cattle or used as manure/fertiliser. I know oilcakes were fed to cattle as late as the 1950's."

I haven't a clue why it would be compared to power steering fluid...

beerchug

-Eric

That was my confusion. I can understand brake fluid [which is actually a solvent based/oil product or transmission fluid, or hydraulic fluid (which is also covers transmission fluid, and/or a variety of oils to be compared. LINSEED OIL? Whats it used for?

I think this is a school project that you will have to setup and do the comparison yourself. I have no doubt that someone has developed a viscosity curve for linseed oil using temp and/or pressure but I am not sure its been enough OR important enough to place on the web.

Since I am kind of an old person I know of times (hmmm last week maybe) that I used transmission fluid for power steering fluid...both are a type of hydraulic fluid...std 10 weight or thereabouts. In some cases its called machine oil. There are differences in fluids yes. I was speaking in general.

I don't know what class you are doing this for, but I believe an Ostwald viscometer is looming in your immediate future. It is a contraption that allows flow rate to be varied as a function of temperature. Then with the use of a formula, which has thankfully been purged from my memory through senility and copious volumes of fermented beverages, you can calculate the viscosity of the fluids at each temp and plot the respective curves.

Your teacher probably picked Linseed oil because it is prone to autooxidation (polymerization). I'm certain the rate of this polymerization increases w/ temp. Thus, the viscosity of the Linseed oil will actually start increasing after you heat it to some magic temperature, which is the opposite of what will happen with the hydraulic fluid. It is Linseed oil's autoxidation property that makes it a good vehicle for paints/inks because it dries (polymerizes) fairly quickly.

Try this.
www.csgnetwork.com/sgvisc.html