I would be interested in calculating the constraint reactions on the 6 pads in yellow in the figure, about 300mm apart among them and loaded with F=12500 kN in blue. Since the system is highly hyperstatic, I don't know how to calculate the constraints. Can you give me a hand?
I've made a FEM...
How can I estimate U and C?
For U I think I have to use the resistance equivalent with thermal conductivity of the glass wall (W/(m·K)) and convection heat transfer coefficient (W/(m2·K))
For C can I assume 2.5 kj/kg/K ?
I know ##\Delta=Q-W##. Here the work done is 0. ##Q## is function of external temperature, wine temperature, the bottle shape and the thickness of glass. Of course the substances are also important (maybe I can consider wine as water, as Jesus did).
I can use conduction Heat Transfer formula to...
Good morning sirs,
I have a standard bottle of wine made by glass, 0.75l.
I suppose it's 20deg and I'd like to know how much time I need to lower the temperature of 4deg, considering outside it's winter, no wind, simple convection.
I read some theory and I discovered some reference to Nusselt...
I think there's a limit below which living becomes unhealthy. I could control it with a thermometer and a hygrometer. 18C–21C is the comfort zone, i think below 18C is better not to go
I have a lodging in a block of 4. Mine is in the lower floor. exposed to east in the living side and to north in the night side.
The average italian consumption is 4% more than minee, but since I'm single and I work/run for the most of the day, my consumption is very high.
A family living in...
Good morning,
I have a 90 mq house burning 1200 smc of methane every year.
I live alone and i keep 20°C when I'm at home (evenings) and 18.5°C when I'm not.
My window frames are quite old, and I don't know very well if it's the case to spend 8 monthly payments to update my hardware.
What is...
Hi,
I notice from the graph that every night when the temperature reaches -2/-3 °C the curve change first the slope and then the concavity.
Is something special happening?
Yes, it's like climbing a mountain and then descending to the same point, but with a different potential.
How can I relate the spinning rotation of the disc with the produced fem? Since the produced current is proportional to the resistance, I think that I have to find a maximum of produced...
Hi,
I was trying to read about the current produced by a dynamo in my physics books but I can't find any reference.
I have a rotor rotating at a certain speed, air flow and with a certain inertia, but how can i find the power produced and related current and tension?
In my opinion I could define ##u=\sin^2(x)+1##, so ##du=2\sin(x)\cos(x)dx##.
Then ##\int_0^{\pi/2}\sqrt{u}du=2(\sqrt2-1)## but this is not the right solution.
Hi,
I'd like to integrate this function: $$ \int _0^ {\pi/2} 2 \sin(x) \cos(x) \sqrt {1+\sin^{2}(x) } dx $$.
I think I should introduce some substitution but I'm not sure. How should I proceed?
Consider that d1 and d3 are parallel at ##\alpha, \beta = 0##. In my attachment there's the correct position in M, but when i have ##\alpha = 90## I can't find the z position.
I can't imagine in my mind how much d3 is raised by ##\alpha## rotation
Hi,
I noticed I used ## \alpha## twice. It's the angle of rotation of d2 and d3 around a axis. It's not the angle between d2 and d3 (that's a constant angle). The 2 degree of freedom are the rotations around a and c axis.
Hi,
I have this scheme, in which there are 3 segments:
- I is coaxial to c axis and free to rotate in the origin. Length d1
- II is coaxial with a axis and free to rotate around c axis. There a fixed angle θ between a and c axis. Length d2
- III is welded to II, it's the PM segment. α is fixed...
Hi,
I made the proof and I notice the piston behaviour is not the same on the outward and inward travel.
For example the damping time changes.
How can I convert this information in a tension [V] on a machine?
Hi, the temperature stands between 20-120 °C, the stroke is about 30-40 mm and the speed is not so high (i think around 1" to perform the complete stroke).
There are no oscillations, the stroke is performed around 10 times a hour, but the system is placed receive vibrations from machining...
Hi,
I have a steel piston running below a 3-4 mm thick steel wall.
I'd need to know the piston position below the wall without drilling the wall. I'm thinking to an inductive sensor but I think it will not work because it will detect all the time something in front of him (the fixed wall)...
This is an angular contact ball bearing.
In the internal side there's a spring pushing to the left, and oil pressure pushing to the right. But the bearings to not bear load, in this case I don't know why they are angular and not straight. Maybe because the passage of the load is not smooth and...
There are 2 spacers: one between the 2 yellow marks (rotating) and the other just above, fixed.
I think the internal is useless since forces are exchanged in other points.
Hi,
In my memories there's the information that in a O shaped mounting, the bearings will work in diagonal (the forces will be transmitted following that path).
But in many drawings I can see the presence of a spacer between internal rings. Is it necessary since no force should be transmitted to it?
This table is used for machining. I have this marketing image in with you can see a general layout (column is around 6m tall).
The main advantage in using hydrostatic technology is vibration dampening.
The hydrostatic rotary tables are the 2 scrolling on the blue bases
Hi,
In some hydrostatic tables I can see many spring-shaped pipes that are traversed by oil.
Spring is responsible for a kind of dampening that I ignore how to deal with.
Do you have any idea of the physical principle behind it?
I think that driving at 130-140 km/h a car could dissipate 5-10 kW of energy only because of aerodynamic drag.
Why cars don't have a fan somewhere to exploit the aerodynamic drag?
For example a Pelton turbine
Yeah, only part of deflection stress formula.
Ok i think i understood. but why ##r^2## into the integral and not simply ##r##?
If i integrate ##r## on ##dA## i will get something related to the area
Hi,
A well-known part of the formula for calculating the deflection stress is ##I_z=\int \int r^2 dA##
Usually a moment of inertia is something related to how difficult is to move an object. In this case is understandable but i don't understand the meaning of the double integral.
Using ##r^4##...
In my opinion the problem is similar for both circuits. When i switch on I and V should have the same phase. And then, after some time, they would be dephase by inductor or condensator
Not only one? for example the 50Hz at home
At this point i understand the phase practically speaking, for example when some AC motor is not well connected, it will turn in the wrong direction. But in a circuit what does it mean?
V and I shifted by 90deg, what does it mean？
In my idea the tension change after connecting the circuit to a battery is immediate, while the current takes some time before moving. That should be sufficient to prove my question but, so why in a RC circuit the opposite happens?
Since randomness is described by entropy, i think you're asking something like: ##\text{this much change in quantity of water in air gives rise to this much change in humidity}##
Summary: Relation between deformed foil and friction force
Good morning everyone,
i have a small leaf or steel that is bent from one side by a Pressure of many bars.
in front of the leaf there's a rotating disk, separated by the leaf by a small gap.
this leaf, as it deforms, wins the gaps and...
Good morning sirs,
let's imagine a cylinder, surrounded on 360° by a coating of the same shape. I can close the 2 half using 2 bolt screws.
what's the maximun transmittable torque?
here's a scheme:
i would to consider the sum of forces as a normal force on the top of the cylinder, producing a...