Thread Subject: Connection port and user-defined domain question?

I customized a domain and several components,but the connection port of the components turn out to be round connector port other than the square ones.
Maybe, these result form inappropriately defined domain.
My question is:
1. Can a domain(or a node) has more than one Across Variable or more than one Through Variable ?
2. Why signal line can not connect more than two round connector of the components? For example, there are three square connectors. Firstly, A connect B by signal line AB.Secondly, you can connect C to A and B by inserting junction point automatically to line AB.
3. Is there some advice on a customized domain with one across variable and two through variables? Can simscape handle this domain and its component?

Long for your reply.Thank you!

"li min" <limingph@gmail.com> wrote in message
news:gr22ih$8m4$1@fred.mathworks.com...
>I customized a domain and several components,but the connection port of the
>components turn out to be round connector port other than the square ones.
> Maybe, these result form inappropriately defined domain.
> My question is:
> 1. Can a domain(or a node) has more than one Across Variable or more than
> one Through Variable ?
> 2. Why signal line can not connect more than two round connector of the
> components? For example, there are three square connectors. Firstly, A
> connect B by signal line AB.Secondly, you can connect C to A and B by
> inserting junction point automatically to line AB.
> 3. Is there some advice on a customized domain with one across variable
> and two through variables? Can simscape handle this domain and its
> component?
>
> Long for your reply.Thank you!

For your first question, yes. An example of that would be a pneumatic
domain, where you would have two across variables (pressure and temperature)
and two through variables (mass flow rate and heat flow).

I don't really understand what you mean with your second question. Can you
try to explain it differently? You can connect many components to one node,
by branching the physical connection to the different components.

For your third question, I am not sure because normally, for each through
variable, you would have a corresponding across variable. What exactly are
you trying to achieve by doing this?

Arnaud

"Arnaud Miege" <arnaud.miege@nospam.mathworks.co.uk> wrote in message <grj33l$me3$1@fred.mathworks.com>...
>
> "li min" <limingph@gmail.com> wrote in message
> news:gr22ih$8m4$1@fred.mathworks.com...
>
> For your first question, yes. An example of that would be a pneumatic
> domain, where you would have two across variables (pressure and temperature)
> and two through variables (mass flow rate and heat flow).
>
> I don't really understand what you mean with your second question. Can you
> try to explain it differently? You can connect many components to one node,
> by branching the physical connection to the different components.
>
> For your third question, I am not sure because normally, for each through
> variable, you would have a corresponding across variable. What exactly are
> you trying to achieve by doing this?
>
> Arnaud
>
Arnaud,
For my second question, I solved it by accident. Maybe, there is some mistake with program installing.
For my third question, for example, liquid-gas two-phase flow in pipe, there are two through variable ( liquid flow rate and gas flow rate), but one across variable(pressure).
for another example, something like:
http://www.mathworks.com/matlabcentral/newsreader/view_thread/253250

limin

"li min" <limingph@gmail.com> wrote in message
news:h0ndq9$jo4$1@fred.mathworks.com...
> "Arnaud Miege" <arnaud.miege@nospam.mathworks.co.uk> wrote in message
> <grj33l$me3$1@fred.mathworks.com>...
>>
>> "li min" <limingph@gmail.com> wrote in message
>> news:gr22ih$8m4$1@fred.mathworks.com...
>>
>> For your first question, yes. An example of that would be a pneumatic
>> domain, where you would have two across variables (pressure and
>> temperature)
>> and two through variables (mass flow rate and heat flow).
>>
>> I don't really understand what you mean with your second question. Can
>> you
>> try to explain it differently? You can connect many components to one
>> node,
>> by branching the physical connection to the different components.
>>
>> For your third question, I am not sure because normally, for each through
>> variable, you would have a corresponding across variable. What exactly
>> are
>> you trying to achieve by doing this?
>>
>> Arnaud
>>
> Arnaud,
> For my second question, I solved it by accident. Maybe, there is some
> mistake with program installing.
> For my third question, for example, liquid-gas two-phase flow in pipe,
> there are two through variable ( liquid flow rate and gas flow rate), but
> one across variable(pressure).
> for another example, something like:
> http://www.mathworks.com/matlabcentral/newsreader/view_thread/253250
>
> limin

I'm not sure how you would handle mixed-phase flow. There are no rules about
the number of through and across variables in a domain, but it's generally
good practice to have a pair of through and across variables. In your case,
would it be possible to have the liquid pressure and the gas pressure? The
overall pressure can then be determined by multiplying each pressure with
the corresponding fraction. It's something I've never dealt with, so I'm not
too sure what the best way to approach this is.

Arnaud