Mixing and fast chemical reaction-VIII: Initial deformation of material elements in isotropic, homogeneous turbulence
✍ Scribed by J. Baldyga; J.R. Bourne
- Book ID
- 103008107
- Publisher
- Elsevier Science
- Year
- 1984
- Tongue
- English
- Weight
- 530 KB
- Volume
- 39
- Category
- Article
- ISSN
- 0009-2509
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✦ Synopsis
The kinematics of the deformation of fluid elements, having a size on the order of the Kolmogoroff velocity microscale, are needed when describing fast reactions in turbulent fluids as competition between molecular diffusion and chemical reaction in shrinking laminae. Starting from the statistical theory of turbulent diffusion, a new kinematic relationship has been derived, which appiies to short diffusion times. Comparisons with two previously used equations, valid for simple shear and a certain elongational flow, confirm the useful properties of the new equation. Its application to fast reactions requires knowledge of the k&m&tic viscosity of the fluid, the rate of energy dissipation (e.g. by stirring) and the initial thickness of the laminae. The parametric sensitivity of the predicted product distribution from fast, competitive, consecutive reactions with respect to the initial thickness, which is on the order of the Kolmorgoroff scale, is relatively low.