PDF modeling and simulation of premixed turbulent combustion
نویسندگان
چکیده
The use of probability density function (PDF) methods for turbulent combustion simulations is very attractive because arbitrary finite-rate chemistry can be exactly taken into account. PDF methods are well developed for non-premixed turbulent combustion. However, many real flames involve a variety of mixing regimes (non-premixed, partially-premixed and premixed turbulent combustion), and the development of PDF methods for partially-premixed and premixed turbulent combustion turned out to be a very challenging task. The paper shows a promising way to overcome this problem by extending existing PDF methods such that a variety of mixing regimes can be covered. The latter is done by a generalization of the standard scalar mixing frequency model. The generalized scalar mixing frequency model accounts for several relevant processes in addition to velocity-scalar correlations that are represented by the standard model for the mixing of scalars. The suitability of the new mixing frequency model is shown by applications to several premixed turbulent Bunsen flames which cover various regimes ranging from flamelet to distributed combustion. Comparisons to existing concepts focused on the inclusion of reaction effects in mixing frequency models for nonreacting scalars reveal the advantages of the new mixing frequency model. It is worth noting that the same methodology can be used in corresponding filter density function (FDF) methods.
منابع مشابه
Three-dimensional PDF simulation of a piloted turbulent non-premixed jet flame
Turbulent combustion is an important process in many technical applications, e.g. industrial gas furnaces used for heating water, production of steam and combustion in jet and diesel engines. To control the turbulent combustion, simulation tools with predictive power are required. The basic equations for turbulent combustion are well known, but their application to the complex flows appearing i...
متن کاملSmall scales, many species and the manifold challenges of turbulent combustion
Amajor goal of combustion research is to develop accurate, tractable, predictive models for the phenomena occurring in combustion devices, which predominantly involve turbulent flows. With the focus on gasphase, non-premixed flames, recent progress is reviewed, and the significant remaining challenges facing models of turbulent combustion are examined. The principal challenges are posed by the ...
متن کاملTransient Combustion Modeling of an Oscillating Lean Premixed Methane/air Flame
The main objective of the present study is to demonstrate accurate low frequency transient turbulent combustion modeling. For accurate flame dynamics some improvements were made to the standard TFC combustion model for lean premixed combustion. With use of a 1D laminar flamelet code, predictions have been made for the laminar flame speed and the critical strain rate to improve the TFC (Turbulen...
متن کاملLarge-Eddy Simulation of Turbulent Combustion
In recent years, Large Eddy Simulation (LES) has been successfully applied to non-premixed and premixed turbulent combustion problems [1, 2, 3]. In most technical combustion applications, the pure non-premixed or premixed combustion models are no longer valid, since partially premixed combustion has to be taken into account. An example is the stabilization region of a lifted non-premixed flame....
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Monte Carlo Meth. and Appl.
دوره 14 شماره
صفحات -
تاریخ انتشار 2008