# Enthalpy for Energy

 Register Blogs Members List Search Today's Posts Mark Forums Read

 October 19, 2005, 18:21 Enthalpy for Energy #1 Daniel Guest   Posts: n/a Hello all. We have lots of different forms of the energy equation we could use. But i read recently that invariably the engineering field use the Enthalpy of Specific Enthalpy in a simulation with chemical reaction. I would like to know why this form is chosen rather than any other form of the internal energy equation? Is it just based on tradition, or are there logical reasons why this method is best suited to a particular flow problem. Any thoughts? Thankyou.

 October 21, 2005, 14:12 Re: Enthalpy for Energy #2 Dino Guest   Posts: n/a I think it is tradition. I have done lots of combustion simulations using the thermal internal energy equation, and it works just fine. The big numerical advantage of not using the enthalpy equation is that there is no dP/dt term to deal with. But the enthalpy equation has been used successfully by a lot of people, so take your pick.

 October 21, 2005, 17:51 Re: Enthalpy for Energy #3 andy Guest   Posts: n/a There are a number of factors influencing the choice of which 2 thermodynamic variables to use. Pressure or density is usually one depending on low or high speed flow but other factors may shift the choice. The other energy-related quantity is often enthalpy but other common choices are internal energy, entropy and temperature. It often depends on which quantity is the best to conserve numerically given the overall solution procedure. It will vary depending on the solution strategy and "invariably" is not correct except, possibly, within a particular solution procedure.

 Thread Tools Display Modes Linear Mode

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post Tomik FLUENT 0 March 14, 2006 12:49 Atit Koonsrisuk CFX 2 December 19, 2005 03:33 mspark CD-adapco 1 April 1, 2004 06:20 BK CD-adapco 2 March 3, 2004 22:29 Martin FLUENT 1 January 25, 2001 18:11

All times are GMT -4. The time now is 07:04.