I am a mechanical engineer but mostly worked on mechanisms and mechanic things. Now I have a heat problem and I guess my heat knowledge is too rusty for this. So can you help me?

The problem is, I have a rectengular prism box with known thickness. Inside, there are some electronic devices. The heat generation of the devices is known. Ambient temperature is known. How can I calculate the temperature of the inside of the box.

Assumptions:

- The box is a flat kind. So the upwards...

Temperature Rise Inside Enclosure]]>

Minimum Force Required for Cutting]]>

As explained in the title, I have a particular...

Equation for the spring constant of an orthotropic, rectangular wire spring]]>

Let's assume that "x" is a function of 6 independent variables a,b,c,d,e,f,g.

From experimental data i have developed 6 functions, each representing how "x" changes by each of the paremeters when the other 5 have a specific value.

So, what i have right now is for example: 1. x=f1(a,1,2,3,4,5)

2.x=f2(6,b,7,8,9,10)

3. x=f3(11,12,c,13,14,15)

......

6.x=f6(16,17,18,19,20,g)

What I need is to...

Development of multivariable function]]>

As part of our "smart factory" policy, our company decided to change all our inventory cabinet to use vertical carousel cabinets, where items would automatically rotate to an opening and operators would easily press a button to get items that they need. My design is very similar with this design http://www.jtechcom.com/samples/vertical.pdf

I am in charge of the design, and being an automation designer, I have found many obstacles in the mechanism of the...

Vertical carousel cabinet calculations]]>

I know that for an object at rest, in order to move it, first STATIC FRICTION must be overcome

(

However, is this the same for an object with wheels? Must the same STATIC FRICTION be overcome first? And then when in motion, ROLLING FRICTION becomes the resisting force? If so, is STATIC FRICTION for an...

Minimum force required to move an object]]>

I was...

Suspension position for suspension pedestal]]>

After a bit of help if possible.

How do I go about calculating the horizontal reaction forces for points A and B on the attached pic. Again I am going to assume the principles of static equilibrium ∑ Fx = 0 ...∑ M = 0

I understand that all forces must 'balance' however, do I need to take into consideration all measurements etc? How do I go about that?

Thanks for any help. View attachment 730]]>

I need to calculate a point load on the above type of beam.

Its overall length is 2.3m, load is applied at 0.500m with a force of 43.0N

How can I calculate/formula the reaction force? and reaction moment?

Thank you for your help. View attachment 714]]>

This is a calculator using rule of thumbs and therefore to be used for rough estimation purposes only.

Download here:

00 HVAC Calc.xls - 910 KB

Good luck!]]>

Does Flow Rate Play a Role in the Prevention of Freezing?]]>

Recently I have been studying for the PE exam for Mechanical Engineers. I have been out of touch of studying for some time so I am having difficulty with some problems. These problems are not necessary difficult but I can't seem to understand how to go about solving them.

Problem 1)

A blimp contains 10000 lbm (4500 kg) of hydrogen (specific gas constant=766.5 ft-lbf/lbm-R (4124 J/kg.K) at 56 F (13 C) and 30.2 in HG (770 mm HG). What is its lift if the hydrogen and air are in...

Buoyancy Problems]]>

I want to design my own spring loaded lubricator. The reason for this being is that the only off the shelve lubricators come in capacities of 125 ml and 220 ml max. I would like to create a 2000 ml spring lubricator.

I have first designed a spring with spring constant k = 22000 N/m.

With the spring constant k I want to calculate the force required to compress the spring by 200mm.

The piston attached to the spring has an area of 0.01 m^2.

The pressure then to compress the...

Spring Lubricator Calculations]]>

To say a 3mm radius 90 degree bend.

Seems to me there'd be some tables somewhere we can look up this kind of thing..

Anyone know?]]>

The problem looks like this:

where P = 1000...

Why euler-bernoulli beam theory does not work in this case?]]>

(Belt weight + product weight) x gravity x Friction x Sprocket Radius = Nm

(30kg + 1kg) x 10 x 0.3 x 0.13m = 6Nm

Which seems really small, am I doing something wrong here?]]>