外文翻譯--對帶有攪拌器回轉式烘干機的兩相流分析（英文）

1、Two-Phase Flow Analyses In Rotory Dryer With Agitator Seong-Oh Jeona, Sung-Hoon Choa, Geun-Yong Songb and Youn-Jea Kimc a Graduate School of Mechanical Engineering, Sungkyunkwan University 300 Cheoncheon-dong, Suwon 440

2、-746, Korea, devilcrow@skku.edu, skkuakela@skku.edu b International Environment Top Co., LTD. 522 Dangjeong-dong, Gunpo 435-833, Korea, visithome@hanafos.com c School of Mechanical Engineering, Sungkyunkwan University

3、 *300 Cheoncheon-dong, Suwon 440-746, Korea, yjkim@skku.edu (Corresponding Author) Tel: +82-31-290-7448 / FAX: +82-31-290-5889 Abstract. The rotary dryer with agitator is an apparatus that combines convection drying as

4、 hot air and rotary drying with agitator. One of the important design factors to decide the drying efficiency is inside flow characteristics of the chamber. It depends on shape, material, rotational velocity of impelle

5、r and velocity of hot air. In this study, we calculated flow fields in dryer chamber with various conditions by a commercial CFD code, ANSYS CFX. Because inside flow of dryer chamber is consisted of hot air and vapor,

6、we performed two-phase numerical analyses. Especially, we obtained the volume fraction distribution inside chamber under unsteady and turbulence flow conditions. Keywords: Two-phase flow, Agitator, Rotary dryer, Unstead

7、y flow, CFD (Computational Fluid Dynamics) PACS: Replace this text with PACS numbers; choose from this list: http://www.aip.org/pacs/index.html INTRODUCTION Recently, the problem of disposing kitchen wastes stands out i

8、n all over the earth as hard restrictions to conserve environment. The ways of disposing kitchen wastes are mainly reclamation, incineration and making fertilizer or feed. Reclamation and incineration have problems as

9、selecting site and creating seriously injurious material. So, several governments support a recycling program that is making a fertilizer or feed with kitchen wastes. To make a fertilizer or feed with kitchen wastes, i

10、ts moisture must have been minimized. If the capacity of disposal is low, we use centrifuge method. But this mechanical drying by centrifugation has physical limit. So, it is essential heat drying to dispose kitchen wa

11、ste industrially. Industrial apparatus to dispose kitchen wastes is used complex drying system like rotary dryer with agitator that combines convection drying as hot-air and rotary drying with agitator. This system con

12、sists of heater under chamber, hot stream injector, condenser for recovering vapor that is generated in chamber and agitator to mix waste continuously as shown in Fig. 1(a). The drying efficiency could be deduced from

13、the flow characteristics of the chamber. These are used to decide the distributions of vapor and air in chamber, and determined humidity in chamber. In order to design an optimum shape of dryer, lots of experiments to

14、visualize the inside flow of dryer chamber have been presented. But it has many problems that are spending a lot of money and time to prototype. Therefore, to solve these problems and get optimum design factors, CFD (C

15、omputer Fluid Dynamics) method are used currently [1]. In this study, we obtained the volume fraction to find flow characteristics in chamber by CFD method. Results are graphically depicted and formed to identify the r

16、elation between the design factor and drying efficiency. 375ATTACHMENT I CREDIT LINE (BELOW) TO BE INSERTED ON THE FIRST PAGE OF EACH PAPER CP1225, The 10th Asian International Conference on Fluid Machinery, edited by

17、M. A. Wahid, J. M. Sheriff, N. A. C. Sidik, and S. Samion © 2010 American Institute of Physics 978-0-7354-0769-5/10/$30.00 FIGURE 3. Finite element systems The conservation equations of two-phase incompressible flu

18、ids are given in Eqs. (1)-(4). And, the 3-D turbulent flow in the chamber can be described by the k-ε turbulence two-equation model as shown in Eqs. (5)-(8). [3-5] Continuity equation: ( ) ( )1p N U tα α α α α αβ β γ ρ

19、γ ρ=? + ? = Γ ? ∑ ?(1) Where αβ Γis the mass flow rate per unit volume from phase β to phase α. This term only occurs if interphase mass transfer takes place. Momentum equation: ( ) ( ) ( )( ) ( ) ( )( )1PTNU U U tp U U

20、U U Mα α α α α α αα α α α α ααβ β βα α α βγ ρ γ ργ γ µ+ +=? + ? ? ?= ? ? + ? ? + ?+ Γ ? Γ + ∑??(2)Where Mα describes the interfacial forces acting on phase α due to the presence of other phase. Also, ( ) U U αβ β β

21、α α + + Γ ?Γ represents momentum transfer induced by interphase mass transfer. Volume conservation equation: 1 1P Nα α γ== ∑(3) This equation could be combined with the phasic continuity equations to obtain a transporte

22、d volume conservation equation. When we divide Eqn. (3) by phasic density, and sum over all phases, we can have the following equation: ( )11 1 p N U tαα α α αβ α α β α αρ γ ρ ρ ρ =? ? ? ? ? +? = Γ ? ? ? ? ? ? ? ? ? ? ?