How to create a vector in simulink? I have given an input which has 2 values, one is flow and another is temperature. I don't know how to simulate this model, Kindly, help me

[Akshay Chakrapani]

The input and output from each systems are a vector which has 2 values(flow and temperature). I want to know how to put the vector in the model for the simulations. As of now the values that are to be taken for simulation can be 1

Answer 1

[Paul]

Vector signals are commonly created in one of two ways.

Define the parameters of any source block such that it ouputs a vector signal. That vector signal then propogates downstream. For example, setting the Amplitude parameter of the Sine Wave block to [1 2] wll cause the ouptut to be a vector signal of time with two sine waves, the first the amplitude 1 and the second with amplitude 2.

Or, use the Mux block to comonbine two or more signals (scalar or vectors) into a vector ouput that propagates downstream.

If neither of these are the solution, more info will be needed on the specific problem.

[Akshay Chakrapani]

I want to combine two variables ( I.e. Flow(Vector) and temperature(scalar)). I have attached a code within

function [y,dT_p]=fcn(u,V_p,P_p,T_p)
% u is the input port to the bloc%
% y is the output port of the block
% T_pin is the input temperature to the block
% T_p is the output temperature from the block
% u contains both flow (u(1)) and temperature (u(2))
% y contains both flow (y(1)) and temperature (y(2))

y=zeros(2,1);
y(1)=u(1); 

if u(1)>=0
   T_pin=u(2);
   y(2)=u(2);
else
   y(2)=0;
end

dT_p=(abs(u(1))*(T_pin-T_p)+P_p)/V_p;

[Paul]

The Inport that flows to u must output two elements.

If this diagram is at the top level of the system, see this doc page for information on how to configure top level inports.

If this diagram is for a subsytem, the signal feedbing that inport from the outside has to have at least two elements.

Also, variable T_pin is not defined on the "else" path of the if statement, which will also cause problems.

[Akshay Chakrapani]

Thank you for the help!

I'm not that accustomed with Matlab but i understood that i have to include 2 elements in the inport that is linked to u right? and similarly the same should be the case for y (output)

Can you help me in how to give 2 elements to it? should i do it in matlab or simulink?

variable T_pin was supposed to be the output of another subsystem which is linked to the one which i shared, I'm really sorry to bother you with such questions

[Akshay Chakrapani]

I will include the T_pin in the else statement

[Paul]

Yes, the output of the inport should have two elements. As previously stated, the way to ensure that depends on whether the inport is in the top level of the model or in a subsystem. I can't show how to do that because I don't know enough about the model.

When it's all hooked together correclty, y will also have two elements. I don't think anything in particular will need to be done for that.

[Akshay Chakrapani]

I will give it a try! Thank you very much :)