Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Units (Time in hour)

Status
Not open for further replies.

mba0188

Mechanical
Joined
Feb 14, 2013
Messages
23
Location
TN
Hello everyone,

I want to use the hour as unit of time because I'm running a model where a long thermal endurance cycle is applied in time, after that I will calculate the mechanical deformation resulted. I can't use the second in due to the large simulation time. Do you know in this case what must be the units of :
Thermal conductivity
Specific heat
Density
Young's modulus

Many thanks in advance
 
well correct me if I am wrong, but since all those quantities do not contain time in their units, I think you don't have to change the units at all !?
 
ok,sorry wrong...
e.g. if you have the young's modulus is kg m^-1 s^-2 = kg m^-1 (1/3600)^-2 hour^-2
i hope this is right... basically you substitute second by 1/3600 h ...
 
You don't convert Young's modulus (as this is force/area), only the thermal conductivity. As this is W/m K, say, and W are J/s then you want J/hr = J/3600s. Remember that you also need to change the units of the film coefficient too and any other units that have Watts in them. If you're using imperial units of Btus then I have no idea. Personally I just leave everything in seconds and simply divide the time by 3600 at the end of the analysis for presentation purposes.

 
Thank you for all your responses.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top