Viscosity: kinematic to dynamic

[lyndsay4321]

hello again,

does anyone know how you would convert 450centistokes kinematic velocity into a dynamic velocity???

many thanks

 

[Guidoo]

That's an easy one:

Dynamic viscosity = kinematic viscosity x density

Other useful stuff:

1 cSt = 10^-6 m2/s
1 cP = 10^-3 Pa.s = 10^-3 kg/(m.s)

So, for water at 20°C:

Dynamic viscosity = 1 cP = 10^-3 kg/(m.s)
Kinematic viscosity = 10^-3 kg/(m.s)/1000 kg/m3 =
10^-6 m2/s = 1cSt

 

[25362]

For example, if you have a bright stock lube with a kin. visc. of 450 cS at 40^oC, and a density at that temperature of 920 kg/m³, the dynamic (or absolute) viscosity would be: 450x0.92 = 414 cP.

1 cP (centipoise) = 0.001 kg/(m.s)
1 cS (centistoke) = 0.000001 m²/s

The only requirement for the conversion is that the temperature for measuring the density should be the same as that used for measuring viscosities.

 

[quark]

ok. I will consider kinematic velocity as volumetric velocity and dynamic velocity as mass velocity (but I have to change the units..eh)

Regards,

 

[CARF]

The unit converter on this page may be helpful:

http://www.carf-engineering.com/

Download this freeware tool.

Cheers,
MVD

 

[chicopee]

Here are the english units conversion equivalancy:

6.72*10^-4* Value(centipoises)= 6.72*10^-4*value (lbm/ft-sec)

6.72*10^-4*value (lbm/ft-sec) /[rho(lbm/ft^3)]=
6.72*10^-4*value/rho (ft^2/sec)

rho-density of fluid

 

[katmar]

Hi Lyndsay,

I have written a utility program called "Uconeer" that will do many conversions for viscosity. It can convert a dynamic viscosity from one set of units to another, and similarly for kinematic viscosity.

It also includes a calculator to convert between dynamic and kinematic viscosities by entering the density. It is very flexible because you can select whatever units you want for each of the viscosities as well as for the density.

This is a freeware program and can be downloaded from

http://www.katmarsoftware.com

 

[quark]

Katmar!

I recently saw your conversion tool upon mentioning by Phex two threads below. It's a nice program and you really did a good job.

PS: I generally use Convert It whenever I get bored of doing manual conversion.

Regards,

 

[phex]

yes, i have to comply with quark, uconeer is a marvelous little helper, and i recommend it whenever there is a question about unit conversion.
good work, and thanks for sharing it to all of us.

bye,
chris

 

[katmar]

Hi Quark and Phex,

Thanks for your kind words about Uconeer. I can't allow my bias to show through by telling everyone about my software, so I appreciate it when people like you do it. I'm sure others would much sooner believe a neutral person than the author of a program.

I always think we software authors are like new mothers - our babies (ie programs) are the most beautiful in the world (in our eyes)!

Quark, I would appreciate your views on why you prefer to use Convert It (which is a very good program) rather than Uconeer. I am always keen to find out what other people really want/need/enjoy in programs.

regards
Harvey

 

[TD2K]

Uconeer is a very nice program. I also use Josh Madison's Convert program. Nice little executable, has most units that I typically need to switch between though Unoceer is far more extensive.

 

[CARF]

This is a good and free unit converter too:

http://www.pawprint.net/vv/download.php