Search results for query: *

Hello, I'm working on an application where I would like to mix two streams of water at different temperatures, to make one stream of water at a uniform temperature. I don't know the exact flow rates yet but the application is for cooling a scientific instrument and the pipework will be ~1/2"...

Hello, thank you for the comments received and I apologise for the delay in responding. Supercritical helium is a compressible fluid. To give an example I've chosen some arbritrary values. I've selected a 10mm diameter transfer line that is 50m long. Through this flows 10g/s of helium with an...

Hello everyone, I've been asked to investigage a cryogenic transfer line that is carrying supercritical helium. This isn't my area of expertise and I'm struggling to find help, our previous Cryogenic engineer left in a hurry and I can't find anything in the literature although I'm probably...

Thank you George and Pierre, I'll follow up on your recommendations. Also on Pierre's point about using a sub-contractor, we're planning to do this later but want to do some in house exploration first so that we're a more informed customer.

Hello, I wonder if someone could advise on a good book for heat exchanger design? I'm responsible for a system where that requires several heat exchangers. We know that these are liekly to be operating at several different but steady operating points. We're going to have to pick the best...

Hello, I wondered if anyone could help in recommending a software package for analysing a manifold flow. This manifold has dividing and combining flows. I've previously analysed a similar system following an example given in Miller's Internal flow Systems book. Where I looked up loss...

Thanks for the help, I had checked Roark but had missed the section on contact. I'll check Roark as that's the book I've got to hand.

Hello, I'm looking at a problem on an assembly in tension. This could be assumed to be a clevis pin arrangement where several plates are joined together using a pin. The holes in the plates are clearance holes and are a slightly larger diameter hole. I'd like to calculate the contact stress...

Hi HPost, Thanks for the reply. For the time being I'm assuming that a high level of control is needed with the minimum overshoot. So a PID controller would probably be required. What I'm not entirely clear on is exactly what needs to be controlled, is it just the mass flow through the valve or...

Hello, Thanks for the responses. The door will be used open and close access for an industrial process and will be in a hard to access location. The door has ~1m of travel. It should take 1.5 seconds. At the moment it's been assumed to reach the constant speed after .5 seconds and to stay at a...

Hello, Thanks for the replies. The hydraulic motor is being used to move a door. The door is mounted on a linear guide and is attached to a ball screw to convert the rotary motion to linear motion. The motion profile will be a standard trapezoidal profile, ramp from 0 at a constant acceleration...

Hello, I've been asked to build a system that uses a hydraulic motor to drive it. I've worked out the torque and rpm required at various times throughout the drive phase of motion. I'm not sure what is required from the power pack to give the required flow and pressure to turn the motor and how...

Hello, Thank you for the replies. Similar to your suggestions I've come across a paper that recommends that the surface should be rough in order for the two mating faces to punch through the oxide layer to make a better contact. One of the questions I'm coming across is thermal cycling of the...

Hello, I'm working on a project that involves bolting two aluminium bus bars together. I'm after some information about how to created the bolted joint. Is there a recommeded surface roughness and flatness for the two mating parts? I've found a reference from Bruker that mentions a German...

Hello, I've got an odd problem. I'm using a command snippet in workbench for some post processing of a thermal analysis. For some reason after a while ANSYS won't let me edit the snippet, generally I can run the solution a few times and am able to edit the snippet. After a while it will no...

Hello, Can someone point me in the direction of a boiling curve for water at 155 bar as used in pressurised water reactors? The only curves I can find are for water at 1 atmosphere. Many thanks

Hello, Thanks for the tips. I've found that THK include a very useful guide on how to select a ballscrew, this is in the back of the one of their ball screw catalogues and includes an easy to follow worked example. One quick question I've got that I'm hoping people can answer. If I were to...

Thanks for the tips. For the application in mind size and packaging will probably be a constraint so having a ball screw made to a custom size would be preferable.

Thanks for the tip. I've found good worked examples that have helped. One of my questions regards ball screws. I've been looking on the THK website, I'm not sure about the length of the ball screw itself. I thought they came in standard lengths. However when I go to the download section of the...

I'm very new to automation and am lookng for some guidance. I'm looking at building a system that uses a motor, leadscrew and a linear guide as part of an actuation system that will move a door approximately 1m. The door itself will weigh about 100kg. As a starting point I was thinking of...