How can I model a fluid collection pan in SimScape, where spilled or sprayed fluid is gathered in a collection volume and then pumped into the system using an intake component

I am building a 1D model of an IC engine’s oil-flow circuit to understand the flow distribution through the nozzles used to represent the physical system. The 1D model is being developed from the engine’s 3D design.

Now I need to model a pan system that collects all the sprayed, spilled, and drained oil so it can be fed back into the circuit through an intake with an appropriate flow resistance to represent the oil filter.

How can I implement a pan that collects all the spilled or sprayed fluid and then returns it into the system through an intake in Simscape? I am using the Thermal Liquid domain because the fluid properties and heat rejection vary with temperature.

[Yifeng Tang]

Is the oil in the pan pressurized at all? I would expect it's not but want to verify.

I think you can use a Tank (TL) block to model this.

[Mekala Suhas]

I have tried that, but was wondering whether constant volume chamber is better to use or not

And In both cases, my problem is whether the flow is going in the direction I want it to.

Suppose I take the Tank(TL), then A would be my outlet and the remaining (B, C, D) would be my inlet back into the tank. It is always triggering a warning that the total Volume of the tank cannot be adhered to, whereas, with the constant volume chamber, I am not able to bring enough flow rate to match the experimental results.

also I dont know whether the flow is going from A and coming back from the rest.

[Yifeng Tang]

The "total Volume of the tank" warning or error is probably due to the tank parametrization and initial conditions. Do you have a simple model that you can share?

A constant volume chamber is a volume FILLED with the liquid with no volume to expand or shrink. It'll behave differently than your oil pan.

In most of Simscape blocks, including Tanks and Chambers, the direction of the flow doesn't matter when building a model. A, B, C, or D can all be used as both inlet and outlet, and can switch direction during the simulation. The solver will find out the direction of mass and energy flow based on pressure difference or flow source you put in.

[Mekala Suhas]

Thank You for the prompt Reply.

I tried the Tank(TL) and I understand that port act as both inlet and outlet in MATLAB, So I put check valves to regulate the flow direction, but it instead caused a pressure spike, resulting in total model's failure.

I have been trying to correct it, but no progress yet. I even removed the check valves to see how they are acting and the flow direction changed. Instead of all the flow going out from A alone, the flow is going out from All but one port. Only one port(connected to the nozzle) is working as the inlet and pressure is now very high at that port and thus model is failing again.

I have changed the design slightly and have replaced my complicated systems with resistances for the simple model, Please refer and help me out

Answer 1

[Yifeng Tang]

A few things I modified:

(1) initial conditions of the two tank. the initial level was left "gray", i.e. default, but the default is 5 m with high priority. need to check it, and set the priority to "none". otherwise it's in conflict with the volume initial target, causing unexpected initial level.

(2) the initial temperature of the lower tank (pan?) is in conflict with the temperature source connected. I set the initial temperature in the tank to be consistent at 313.15K.

(3) the "intersection" tank is set up to require a pressure input signal. I don't think there is a good way to find out what it should be, and I also don't think this tank is necessary. If it's indeed just an intersection, i.e. a volume in the fluid circuit, you may use a constant volume chamber. If the volume isn't significant, just use ... nothing.

The model runs without error now, but whether it's simulating what you intended, I'll leave it to you to decide. Also, I would suggest that you only use check valves where there is indeed a check valve in the real system.

[Mekala Suhas]

May I know all the changes you did for no error

Model is running smoothly, but the liquid flow is inconsistent with the experimental values.

I have tried it now, still shows very high pressure at Port E in Oil Tank Main

If I try to sort that, then it shows that residual norm is too high.

[Yifeng Tang]

You can do model comparison in MATLAB. It works just fine with Simulink models.

Whether the model matches your test results depends on whether you've built the model to represent your system AND whether the componenet parameters are consistent with the actual components. Unfortunately, I can't comment on either as I have no knowledge of your system or components.

[Mekala Suhas]

I dont have a model to compare to, But I did try it with my expermental results.

I will see what I can do

Thank you for the invaluble help @Yifeng Tang

I was able to clear many issues thanks to you.