Numerical modeling of turbulent dispersion around structures using a particle-in-cell method
In this paper, a methodology is described wherein two numerical models are exercised in order to predict the turbulent transport and dispersion around a surface-mounted rectangular block. This methodology can be expanded in the future to treat more irregularly-shaped single buildings or clusters of buildings. The calculational procedure which is proposed consists of two separate steps, namely: (1) prediction of the turbulent wind field and (ii) employment of the calculated wind field to drive a transport-dispersion model. It is well known that external flow past non-streamlined bodies is usually very complex, exhibiting separation and reattachment regions, high pressure gradients and turbulence levels, and unsteadiness. The approach employed is to solve the Reynolds-averaged Boussinesq equations with turbulence represented via a k-{epsilon} model. This particular turbulence model has been applied extensively to many classes of flows including those which are influenced by buoyancy, stratification and rotation effects. It has a good reputation for reliability and is also computationally economical compared to more complex models. Recently, a number of calculations of turbulent flows over surface-mounted cubes which use a k-{epsilon} turbulence model in conjunction with finite-difference techniques were presented. In contrast, the flow model developed in this paper uses a modified finite element method (FEM). A K-Theory version of this model has been employed to simulate flows which describe the dispersion of heavier-than-air gases and the atmospheric boundary layer. The present model is algorithmically identical to the earlier model except two additional equations were required for the turbulence model and a building-block specification is used to represent structures for computational efficiency. 9 refs., 6 figs.
- Research Organization:
- Lawrence Livermore National Lab., CA (USA)
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (USA)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 5898117
- Report Number(s):
- UCRL-JC-105271; CONF-910659-5; ON: DE91009757
- Resource Relation:
- Conference: 84. annual meeting and exhibition of the Air and Waste Management Association (AWMA), Vancouver (Canada), 16-21 Jun 1991
- Country of Publication:
- United States
- Language:
- English
Similar Records
Development of a building wake/stack height numerical modeling capability
A finite element/finite difference approach for modeling three- dimensional flow and pollutant dispersion around structures