a compendium of tech stuff

Aug 19, 2012

On 5:06 PM by Lalith Varun   8 comments

          FLUENT is a computational fluid dynamics (CFD) software which consists of modeling capabilities needed to simulate flow, turbulence, heat transfer and chemical reactions for a wide range of applications. It is an integral part in the design and optimization process of any product development.

          FLUENT has a wide range of boundary conditions that allows the flow to enter and exit the domain. This article helps you in selecting the appropriate boundary conditions for your specific application.

There are about 10 different types of flow inlet and exit boundary condition options in FLUENT.

1) VELOCITY INLET - It is used to define the velocity and other properties of the flow at the inlet. Intended for in-compressible flows

2) PRESSURE INLET - It is used to define the total pressure and other properties of the flow at the inlet. Flow direction must be defined else non-physical results can occur. Suitable for both compressible and in-compressible flows. Outflow can occur at pressure inlet conditions.

3) MASS FLOW INLET - It is used in compressible flows to define the mass flow rate at the inlet. It is not necessary in in-compressible flows as the velocity inlet itself fixes the mass flow rate.

4) PRESSURE OUTLET - It is used to define the static pressure at the outlet. It often gives better rate of convergence when back-flow occurs. Back-flow can occur at pressure outlet conditions and is assumed to be normal to the boundary. This must be used when problem is set up with pressure inlet.

5) PRESSURE FAR-FIELD -  It is used to model free stream compressible flow at infinity, with free stream mach number and static conditions specified. This is available only for compressible flows when density is calculated  from ideal gas law.

6) OUTFLOW - It is used to model flow exits where flow velocity and pressure are not known prior to solution of the flow. It cannot be used for compressible flows, with pressure inlet boundary condition and in unsteady flows with variable density. Can be used with velocity inlet.

7) INLET VENT - It is used to model inlet vents with specified loss coefficient, flow direction and inlet pressure and temperature.

8) INLET FAN - It is used to model an external intake fan with specified pressure jump, flow direction and intake pressure and temperature.

9) OUTLET VENT - It is used to model an outlet vent with specified loss coefficient and discharge static pressure and temperature.

10) EXHAUST FAN - It is used to model an external exhaust fan with a specified pressure jump and discharge static pressure.

          These boundary conditions help design and analyze the domain and model the flow through it.

Go to TOP


  1. Hi, I am Student of IIT Kharagpur. I am trying to simulate an underwater vehicle, ejecting air from its nose or mouth. I am wondering which boundary condition is to be used at nose or mouth of the under water vehicle from where it is ejecting air.

    I will be very grateful to you, if you could help me in this regard.
    please drop me a mail (sumityadavm@gmail.com) or reply in this thread.


    Sumit Yadav
    Senior Student of
    Department of Chemical Engineering
    Indian Institute of Technology Kharagpur
    Mob. no.+91 7501379564 (Kgp)
    E mail- sumityadavM@gmail.com

  2. Hi,

    would you have any idea what the flow direction would be for the pressure far field? I am simulating a supersonic flow in a 2D nozzle jet and require to fill in parameters for X and Y direction.


  3. This really is my very first time i visit here. I discovered so many entertaining stuff in your blog, especially its discussion. From the a great deal of comments on your own articles, I guess I'm not the only one having all of the leisure here! Maintain the wonderful work.temperzone

  4. I really appreciate  DR AKHIGBE,my name is LAURIE HUGHES . I will never stop testifying DR AKHIGBE. Happiness is all I see now I never thought that I will be cured from HIV virus again. DR AKHIGBE did it for me. I have been suffering from a deadly disease (HIV) for the past 2 years now, I have spent a lot of money going from one place to another, from church to church, hospitals have been my home every day. Constant checks up have been my hobby not until this fateful day,  I saw a testimony on how DR AKHIGBE helped someone in curing his HIV disease in internet quickly I copied his email which is drrealakhigbe@gmail.com just to give him a test I spoke to him, he asked me to do some certain things which I did, he told me that he is going to provide the herbal cure to me, which he did, then he asked me to go for medical checkup after some days, after using the herbal cure and i did, behold I was free from the deadly disease,till now no HIV in me again he only asked me to post the testimony through the whole world, faithfully am doing it now,all the testimony of DR AKHIGBE is true  please BROTHER and SISTER, MOTHER and FATHER he is great, I owe him in return. if you are having a similar problem just email him on drrealakhigbe@gmail.com or you can whats App his mobile number on +2348142454860  He can also cure these diseases like HIV and AIDS HERPES,DIABETICS,CANCER, HEPATITIS B,CHRONIC DISEASES, ASTHMA, HEART DISEASES, EXTERNAL INFECTION, EPILEPSY, STROKE, INSOMNIA,  MULTIPLE SCLEROSIS,GOUT,  NAUSEA,VOMITING OR DIARRHEA, LIVER CIRRHOSIS, KAWASAKI DISEASES, LUPUS,ECZEMA,BACK PAIN,JOINT PAIN. .ETC .please email drrealakhigbe@gmail.com    or whats APP him  ..+2349010754824.  He is a real good and honest man.  
    website...  https:drrealakhigbe.weebly.com

  5. Thank You so much for sharing this amazing post. If you want to hire a Pest Control Service in Gurgaon, then connect ZoopGo.

  6. Stunning dispatch! I'm to be certain getting fitting to over this data, is to actually look at ordinarily around made my mate. Comparably stunning web journal here among astounding the confusing data you get. Set aside the standard cycle you are doing here.
    Delhi Hot Girls