1 / 6

MAE 5310: COMBUSTION FUNDAMENTALS

MAE 5310: COMBUSTION FUNDAMENTALS. Coupled Thermodynamic and Chemical Systems: Plug Flow Reactor November 5, 2012 Mechanical and Aerospace Engineering Department Florida Institute of Technology D. R. Kirk. PLUG FLOW REACTOR OVERVIEW. Assumptions Steady-state, steady flow

ami
Télécharger la présentation

MAE 5310: COMBUSTION FUNDAMENTALS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. MAE 5310: COMBUSTION FUNDAMENTALS Coupled Thermodynamic and Chemical Systems: Plug Flow Reactor November 5, 2012 Mechanical and Aerospace Engineering Department Florida Institute of Technology D. R. Kirk

  2. PLUG FLOW REACTOR OVERVIEW • Assumptions • Steady-state, steady flow • No mixing in the axial direction. This implies that molecular and/or turbulent mass diffusion is negligible in the flow direction • Uniform properties in the direction perpendicular to the flow (flow is one dimensional). This implies that at any cross-section, a single velocity, temperature, composition, etc., completely characterize the flow • Ideal frictionless flow. This assumption allows the use Euler equation to relate pressure and velocity • Ideal gas behavior. State relations to relate T, P, r, Yi, and h • Goal: Develop a system of 1st order ODEs whose solution describes the reactor flow properties, including composition, as a function of distance, x T=T(x) [Xi]=[Xi](x) P=P(x) V=u(x) Dx

  3. GOVERNING EQUATIONS Mass conservation x-momentum conservation Energy conservation P is the local perimeter of the reactor Species conservation

  4. USEFUL FORMS Results from expanding conservation of mass Results from expanding the energy equation Differentiation of functional relationship for ideal-gas calorific equation of state, h=h(T,Yi) Differentiation of ideal-gas equation of state Differentiation of definition of mixture molecular weight expressed in terms of species mass fractions

  5. POTENTIAL SOLUTION SET • In these equations the heat transfer rate has been set to zero for simplicity • Mathematical description of the plug-flow reactor is similar to constant pressure and constant volume reactor models developed previously • All 3 result in a coupled set of ODEs • Plug Flow Reactor are expressed as functions of spatial coordinate, x, rather than time, t

  6. APPLICATION TO COMBUSTION SYSTEM MODELING Turbine Air Primary Zone f~0.3 f ~ 1.0 T~2500 K Compressor Conceptual model of a gas-turbine combustor using 2 WSRs and 1 PFR

More Related