Thanks Peter,
I think I'll use Microsoft equation editor for now. I wish Mathsoft would find a way to use literal scripts, e.g. overscript or overstrike & understrike math notation for reports as used in texts.
Bill
Bill Swain
Ultra Electronics Precison Air Systems
Technical Manager-USA
Does anybody know how to inserted dotted notation such as M.dot for mass flow. Or, double dot for acceleration? I would like to use this in a word document for a report, but want o use my MathCad to perform the math.
Thanks,
Bill
Bill Swain
Ultra Electronics Precison Air Systems
Technical...
Alex,
I think I understand it now. You effectively have a two branch feed system going into one that supplies the volumetric flow rate, i.e. GPM, at the cooler. Instead of increasing the source pressure you are trying to combine two streams into one to add more "GPM" through the system...
Too many system's information left out for a proper design. I don't think this forum could give you the answer. Seems like a system's engineering approach is required.
Good Luck,
Bill
Bill Swain
Ultra Electronics Precison Air Systems
Technical Manager-USA
swainw@asme.org
CRG,
Great illustration. The species gradient is inward towards the vapor free stream. The boundry layer at the wall has an effective velocity of zero. This allows molecule migration and then through the diffusion into the flowing stream, getting swept up into. Dry air has a very nice...
Alex,
Your pipework isn't the problem. The losses due to the pipework will be what they are. The acummulator will soften the effect of any pressure fluctuations such as from the rapid opening at the end for service. But, it looks like you will need to increase your pump outlet pressure to...
Sorry,
I was trying to take a comprehensive answer involving enthalpy and put it into what seems to be someone looking for a generic answer of two different fluid flowing terms. What I meant by "ethalpy of the fluid moving the energy, or its capacity to move the energy" was to try to...
Partial Pressures. Remember Boyle's law of partial pressures and the math will show how this occurs. Also, the transfer theory associated with molecular gradients of an constituent drive the entropy of a system to move towards equaliztion. High humidity to low.
The air pressure is a...
Pressure drop across the orifice is significant to your problem. If the flow is choked as in the gas has reached sonic in the throat area the flow rate can be determined from gas dynamics tables. But you will need to know some entrance values such as T to determine the rho, density. This sets...
Wow, what a thread. Actual energy flow is BTU/hr. This takes the form of Q = q*h*dT.
q = gpm as a flow rate.
h = enthalpy of the fluid moving the energy, or its capacity to move energy. h is temperature and fluid type dependent and as such there are many tables for determining the h value...
On a practical note: Having a license or not does not substitute for experience. A mention was made to FEA or proof testing program. The main concern would be to rely soley on a computer program over sound practical engineering. This seems to be an accident waiting to happen.
I work in...
How about a relief valve with an external stem. The stem would move a lever that clanged a bell. My engineering concern is your 10,000psi value. The hydraulic fluid is going somewher when it is relieved?? What action does the valve perform. A gating function to an accumulator?
Good...
Your problem intrigues me, but without knowing the fluid being piped, the pipe properties, and the pump characteristics it would be difficult to determine your losses through the system, the pressure drops, the effect of the resevoir head, etc.
I think you are working with a liquid so the...
Thanks Dave,
You are correct that the spreadsheet uses the row above to calculate the next time step. As mentioned before as long as the boundry condition stays the same, the initial node and those through do fine. But, again reading about the time step, the real world data is set to a 1...
Yes you are correct that I do not have a good feel for what is happening in my spreadsheet. When the temperature stayed constant I thought understood what the rows were iterating on as they were the execution of the finite difference convergence. I believe that in all of the rows prior to 11th...
Thank you,
But I have some more questions and problem definition. I'm not sure what the excel setting does on the calculation you mentioned, but the way I've set up the excel spread sheet is the LH column represents the T.infinity of the outside air Temp. The next 7 columns to the...
Hello,
Im doing some building calcs on a thermal rise of air temperature due to a heat exhanger being installed in a very large whse space for use with a temp chambers refrigeration unit. The equations are pretty straight forward for when the outside conditions are lower that the internal...
We are doing some calcs on cyclinders filled with 5000psi air. the cyclinder is installed in an aircraft and using thermal flight profiles (dT/dt) functions, I am trying to see what the effect of the cylinder housing will have on thermal lag to effecting the internal temperature of the air...
Changing units is fairly simple. I do it all the time. If the unit you want is not in the library such as ksi, use the tilde ~ operator to globally define the value. e.g. ksi ~ 1000*lbf/in^2. Then you can use ksi as a displayed unit.
I just opened my MCAD2001i and it had newtons as N and mm...
I use C Code to perform engineering analysis such as sizing of components structurally, running heat transfer models, etc. These are not windows programs in the sense like parent child windows, with all the API interface, etc. However, My programs have to write to files. Wit today's complex...
