Hello IRstuff-
I calculated T2 using the convective heat transfer equation in the attached file. My T1 started at the lowest operating temperature of 10C and I calculated htc for my material by dividing k by material thickness per wikipedia. I don't know if I trust the 80.853C result for T2...
Hello IRstuff-
Sorry, I haven't done a heat transfer problem for quite some time. Do I need to subract the T2 in your equation 3W=htc*area*deltaT from Q=m*c*deltaT because of the heat transfer to the outside the box? I was first hoping to calculate/graph the inside temperature of my box, but...
Hello Forum-
Thank you for taking the time to review my question.
I'm trying to determine what the maximum inside temperature of a new product will be and to see if the product will need a fan.
The heat sources are various electrical components which account for 3W and a an intermittent...
Hello Btrueblood-
Thank you for the tip, when I moved the sensor to the 400mL volume the extra pressure pulses did magically disappear. How would you explain this? Is this because the large volume isn't affected as the easily as 1/16th tubing's volume? I have a couple other questions, when is...
Hello hydromech-
It looks a lot like under shoot and overshoot, how are you varying the volume of the cylinder?
Engineerrmech: The volume is changed by moving a simple pneumatic cylinder by means of a stepper motor.
Thanks,
Engineerrmech
Hello quark-
May be your pressure transmitter is too sensitive and it may be close to entry and exit points.
Engineerrmech: We do have a sensitive pressure sensor due to it's other uses in the future product. What do you mean "too close to entry and exit points"?
Are you continuously...
Hello BigInch-
I've attached a pdf to show my prototype setup and the fluid is air.
Thank you,
Engineerrmechhttp://files.engineering.com/getfile.aspx?folder=05b7d5e6-8676-4b11-91a6-dbb917fbe85b&file=Eng_tips_flow_chart.pdf
Hello Forum-
I have a question concerning pressure changes. We are trying to make small pressure changes to a static pressure of 5psi by varying the volume in a cylinder. We have had no problem making these pressure changes, but an interesting phenomenon is occurring. At the leading and...
Hi Desertfox,
DESERTFOX: If you reduce the thickness of the spring, you reduce the stiffness of that spring by a cube law.
ENGINEERRMECH: I've never heard of the cube law.
DESERTFOX: So, for a given load, the deflection will be much greater. However, you are correct, if you use 3 springs...
Hi Deserfox-
Desertfox: Okay so the spring moves -x direction 0.25" and pin A also moves in the -x direction what makes the support pin move more in the -x direction than the spring itself.
Engineermech: Pin A is in the handle. There is a pivot point that allows Pin A to rotate while the...
Hi Desertfox-
DESERTFOX:If the spring travels in the -x direction why does it get further away from the pin support?
ENGINEERRMECH: Support A is part of the handle/trigger and deflects moves when compressed.
DESERTFOX: If I understand the deflection correctly :- first the far lefthand end is...
Hi Desertfox-
I attached the first sheet of my pdf with a couple added notes. I made an assumption on the simply supported beam in reality the spring travels in the "-x" direction when the trigger/handle is compressed. The total deflection of the trigger end of the spring is approximately...
Hi Desertfox:
DESERTFOX:I have had a look at the link you gave for the material properties of the SAE1095 steel and your stress values are way above the Yield stress for the material according to your calculations, even though we have already established that your equations are not valid beyond...
Hello israelkk-
There must be equations out there that describe deflections over 30% of the beam length? I'm kind of stumped as where to go. It looks like I can't use the simple equations mentioned above and the ANSYS package we have doesn't work for large deflection? Any suggestions?
Thanks...
Hi desertfox-
DESERTFOX:First thing that struck me was the large deflection relative to the length of beam, ie beam theory which you have used is limited to small deflections.
ENGINEERRMECH: I was worried about the large deflection, but these were the only equations I could find. Is there a...
Hello israelkk-
The two 2D drawings on the first page are a simplification how the spring is loaded. First, the spring is slipped into a channel and supported/loaded as shown in the "Preloaded Experimental" drawing. Then when the trigger/handle is pressed the spring is supported similar to the...
Hello ckozka-
Thank you for taking the time to simulate my problem and supplying me with a pdf. May I ask what SW package you used for the simulation?
Thank you,
engineerrmech