(An) investigation of the effects of interfacial shear between the gas and turbulent falling liquid film on the heat transfer coefficient = 가스와 난류 액막사이의 계면 전단응역이 열전달 계수에 미치는 영향에 관한 연구

Cited 0 time in webofscience Cited 0 time in scopus
  • Hit : 337
  • Download : 0
An improved method is presented for the prediction of heat transfer coefficients in turbulent falling liquid films with or without interfacial shear for both heating or condensation. A modified Mudawwar and El-Masri``s semiempirical turbulence model, particularly to extend its use for the turbulent falling film with high interfacial shear, is used to replace the eddy viscosity model incorporated in the unified approach proposed by Yih and Liu. The liquid film thickness and asymptotic heat transfer coefficients against the film Reynolds number for wide range of interfacial shear predicted by both present and existing methods are compared with experimental data. The results show that, in general, predictions of the modified model agree more closely with experimental data than that of existing models. Comparisons of the predictions of the present model with that of existing models and the experimental data show that agreement is fairly good and consistent. A brief summary of the results are as follows: (1) As opposed to the previous model, present model utilizes a continuous linear variation of eddy viscosity near the interfacial surface. For freely falling liquid film, the present model reduce to the Mudawwar and El-Masri``s model. (2) The curves of the present model for the heat transfer coefficients with liquid film Reynolds number have positive slopes in turbulent regime while the curves obtained by other models have negative slopes particularly for condensation. (3) The two criteria for transition from laminar to turbulent film flow, one for low interfacial shear and the other for high interfacial shear, respectively are shown to give the best agreement with the data for the present method.
Advisors
Chun, Moon-Hyun전문헌
Description
한국과학기술원 : 원자력공학과,
Publisher
한국과학기술원
Issue Date
1995
Identifier
98824/325007 / 000885156
Language
eng
Description

학위논문(박사) - 한국과학기술원 : 원자력공학과, 1995.2, [ xii, 141 p. ]

URI
http://hdl.handle.net/10203/48839
Link
http://library.kaist.ac.kr/search/detail/view.do?bibCtrlNo=98824&flag=dissertation
Appears in Collection
NE-Theses_Ph.D.(박사논문)
Files in This Item
There are no files associated with this item.

qr_code

  • mendeley

    citeulike


rss_1.0 rss_2.0 atom_1.0