As you can see the figure, I gave outlet boundary condition as 20 bar. Actually I want the compressor to calculate the pressure outlet by using pressure ratio.
Can we model a system using fluid libray without outlet boundary condition?
If you just remove sinkP the system will be underdetermined — you'll miss one boundary value. Since the compressor models describe the relationship between pressure difference and mass flow rate you must specify the mass flow rate if you want the model to calculte the outlet pressure. To do so, use a mass flow rate/enthalpy (or temperature) as outlet boundary component instead of sinkP. Remember to specify a negative mass flow rate.
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I've created a Dymola model. It has an empty tank, which is connected to the output of sweptVolume component via a static pipe. Input to the sweptVolume is a constant force, with the help of which I would like to transport water from the hydraulic cylinder to the tank.
I've assumed the cross sectional area of the piston. I've calculated the force that is needed to displace the water in the cylinder assuming the pressure to be atmospheric (101.325kPa). But, somehow I see the water is not getting displaced and the volume is remaining constant without filling the tank.
Please suggest, what type of input should be given for the sweptVolume element (position,move etc.), in case the given input constant force is wrong.
I would like to thank you for your time and interest.
the way to setup initial conditions it is only a matter of GUI, just add "flange(s(start=1, fixed=true))" in add modifiers tab of the sweptVolume parameter dialog in Dymola. To get your model work just invert the sign of the force, the sign convention for the force block is displayed by the arrow, so to compress the piston and fill the tank have to set the const value to minus something. Check the fluid volumes since you will get the model to stop when tank overflows or when piston stroke reaches the end (negative value of s). So you have to setup correctly the forces, or the tank and piston volumes or place some kind of stop to the mechanic part of the piston. The model can work fine even without masses added to the piston.
Hope this helps,
Marco
I have been trying to apply the multiObjectTracking() function from this example to some videos of insect motion on a 2D surface.
In the linked example, a Kalman filter is used for estimating the motion of tracked objects if they are lost for a few frames due to foreground occlusion. The filter is set up using the configureKalmanFilter() method using the 'Constant Velocity' model for motion estimation. Alternatively it can be called with the 'Constant Acceleration' model.
My question is how would I set up a custom model for motion estimation in my Kalman filter?
The primary cause of lost tracks in my footage is when an animal stops for several frames then begins walking again, possibly in a different direction. Therefore i would like to implement a 'No Velocity' model (so to speak) that assumes the lost object has simply remained in its last known location until it is picked up again.
You can create the vision.KalmanFilter object directly, without using the configureKalmanFilter function. In that case, you can pass in a custom state transition matrix. However, since this is a regular Kalman filter (not extended or unscented), the state transition must be linear. So I am not sure what other motion model you can reasonably use, other than constant velocity or constant acceleration.
The specs for the web audio API dynamic compressor node refer to some curve being drawn over various decibel values. How can I visualize that curve?
For filter nodes, the web audio API provides a getFrequencyResponse method that produces data that can be visualized on a 2D canvas.
Is there a similar method for the dynamic processor node? Or are there well-known formulas used to compute the magnitude of the node's effect on various dB values?
I'm not sure exactly how to calculate the curve for knee, but I'm pretty sure it shouldn't be super difficult. Ignoring the knee, here's what you'd need:
First, you'd start out with a line that has a slope of 1 (45 degree angle, up and to the right). Another way of saying that is that output = input
Then, when you hit threshold, you change the slope of the line to match your compression ratio. So if your ratio is 2.3:1, your slope above the threshold would be output = input / 2.3.
Anyway, I'm sure if you do some searching, you can figure out how to factor in the knee. It's probably just a parabola that joins the two slopes (with a vertex at the point where they would normally intersect if the knee was 0). Then you just need to figure out what the value does, but if you read the Web Audio spec, the unit for knee is dB – which leads me to believe this isn't really implementation-specific. I think there probably is a Right Way™ to do it.
Unfortunately there is no way to examine easily the effect of the dynamic compressor node. And the actual implementation isn't specified in the WebAudio spec. The only way to know the effect is to examine the source code. Or perhaps feed a sine wave of different frequencies to the node and examine the output to see what is happening, experimentally. This might be hard to capture the effect of all of the parameters.
I have made a basic "quarter-car" simulink model. It is a double mass system with two springs and two dampers. However I want to add speed of the car as a parameter to this model and I do not know how. Block "Step" is the bump size as an input from the road. Screenshot of the model
Thanks
Your quarter car model is in the vertical dimension only. You wish to add the speed of the vehicle which will then add another dimension to your model. This will require some thought. How do you wish to model the input to the model once the horizontal dimension is developed? I would recommend trying something simple like modifying the "Step" block(which I can't seem to find in your model) to create a larger disturbance at high speeds. Then you can build from there, add profiles to describe road artifacts, etc.
I want to simulate fire using SPH particles. I understand the concept behind SPH but don't understand yet how to model the fire as a fluid.
Do I have to add some temperature property to my particles from which I can derive there color?
Do I have to take the surrounding air particles in account to create some buoyancy effect?
Where do the particles get their heat from? Do I have to add a heat emitter over some space which creates warm particles so that the temperature then diffuses to the other particles over time?
Are there some tutorials which describe my problem?
Yes, you'll have to have a temperature property. It really isn't fire if temperature isn't involved. And once you have temperature it's easy to get luminosity and color. (You probably don't have to worry about radiative heat transfer, at least not for a first effort.)
If you handle pressure and gravity right, buoyancy will arise (ahem) naturally.
You can start with a fixed heating element and an inert gas, then when you're ready you can introduce combustion as a differential equation: the rate of energy generation is a function of temperature, fuel pressure and oxygen pressure.