Closure of non-integer moments arising in multiphase flow phenomena
- 作者：S. Haeri ; J.S. Shrimpton ; john.shrimpton@gmail.com
- 关键词：Fractional moments ; Moment generating function ; Laguerre polynomial ; Closure problem ; Multiphase flow ; Eulerian&ndash ; Eulerian turbulent models
- 刊名：Chemical Engineering Science
- 出版年：2012
- 期刊代码：18_00092509
- 类别：ce
- 出版时间：18 June, 2012
- 卷：75
- 期：Complete
- 页码：424-434
- 文件大小：922 K
摘要
In this paper we consider closure problem for non-integer moments of form which are encountered in the moment evolution equations of many multiphase flow systems involving polydispersed particles, heat and mass transfer, chemical reactions, agglomeration or break-up. Two different categories of methods are considered: the first method is based on the reconstruction of the underlying PDF using Laguerre polynomials and the other is based on the direct calculation of non-integer moments using the fractional derivatives of moment generating function (MGF). By applying the results of fractional calculus an explicit equation is derived to express non-integer moments as a function of any arbitrary number of integer moments. The proposed methods are tested on several highly non-Gaussian analytical PDFs in addition to experimental agglomeration data and direct numerical simulation of fluid-particle turbulent multiphase flows.