ACUSOLVE

Altair Forum User
Altair Forum User
Altair Employee
edited October 2020 in Community Q&A

Hello,

I am working on automobile component i.e. EGR coolar. Here task is to Cool hot gas emitting out from engine and to send back to engine by using coolar i.e. ethylene glycol.

EGR coolar has two fluid gas(hot air) & coolant(Ethylene glycol). Each fluid passing from 1 side. It may be parrallel or counter flow.

I am getting inputs from customer like this, I am showing you 2 case as follows:

 

CASE 1:

Coolant flowing at 90'C @ 1200l/hr @ 2.5Bar-gauge

Exhaust Gas at 450'C @ 150Kg/hr 2Bar-gauge

 

CASE 2:

Coolant flowing at 90'C @ 1200l/hr @ 2.5Bar-absolute

Exhaust Gas at 450'C @ 150Kg/hr 2Bar-absolute

 

Hence some time I am getting input value of pressure in bar or absolute.

I am giving BC like this:

At inlet I am defining pressure and temperature and at outlet negative flow I am giving.

 

But I am not understanding how to value of pressure in gauge and absolute?

 

Regards

Rajendra

BorgWarner Emissions System

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Answers

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited August 2017

    Hi Rajendra,

     

    As discussed we explained about these below parameters…

     

    1.      Calculate density of working fluid at the particular pressure and temperature and use that in material properties.

    CASE 1:

    Coolant flowing at 90'C @ 1200l/hr @ 2.5Bar-gauge   -   use  Coolant properties at this temperature and pressure. here pressure is in Gauge, add atmospheric pressure to make it absolute pressure

    Exhaust Gas at 450'C @ 150Kg/hr 2Bar-gauge   -     use  Gas properties at this temperature and pressure. here pressure is in Gauge, add atmospheric pressure to make it absolute pressure

     

    Regards

    Ravi Harti

     

    Let us know if you face any difficulties in using AcuSolve.

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited August 2017

    Hi,

    By defining the reference pressure as Atmospheric pressure or zero pressure you can switch between the gauge and absolute pressure.

     

    On coolant inlet side: you are given temperature, pressure and flow rate. In case you are modelling the coolant as incompressible media then you can convert the equivalent flow rate for the pressure and apply the total flow rate at the inlet boundary at given temperature.

     

    Coolant outlet bc will depend on the actual flow path of coolant.

     

    Regards