Coefficients of time and length scales of turbulent eddies

Keh-Chin Chang, Shih Shiang Jeng

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

The turbulence time and length scales representing the energy containing eddies are by Tt = CtT k/ε and lt, = Ctl k32/ε, respectively, while the Kolmogorov time and length scales representing the energy dissipative eddies are expressed by Tk = CkT (υ/ε)1/2 and lk = Ckl3/ε)1/4, respectively. The available DNS data for fully developed channel flows with and without wall injection / suction are used to determine the coefficients. It is found that, with the typical values of CtT = Ctl = 1 which are usually adopted in the turbulence study, CkT = 2 and Ckl = 3. However, this set of coefficients lead to underprediction of the thickness of viscous sublayer yVSL+. By relaxing the usual assumption of CtT = Ctl = 1, a new set of coefficients: CtT = Ctl = 0.8, CkT = 4, and Ckl = 9 is suggested. The yVSL+ calculated with this set of coefficients becomes more physically reasonable.

Original languageEnglish
Pages (from-to)193-197
Number of pages5
JournalJournal of Mechanics
Volume18
Issue number4
DOIs
Publication statusPublished - 2002 Jan 1

Fingerprint

Length Scale
Time Scales
Turbulence
vortices
Coefficient
Channel flow
coefficients
turbulence
Channel Flow
suction
Suction
channel flow
Energy
Injection
injection
energy

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics
  • Mechanical Engineering
  • Applied Mathematics

Cite this

Chang, Keh-Chin ; Jeng, Shih Shiang. / Coefficients of time and length scales of turbulent eddies. In: Journal of Mechanics. 2002 ; Vol. 18, No. 4. pp. 193-197.
@article{369c906afa2f419e80d9e39aed019c5a,
title = "Coefficients of time and length scales of turbulent eddies",
abstract = "The turbulence time and length scales representing the energy containing eddies are by Tt = CtT k/ε and lt, = Ctl k32/ε, respectively, while the Kolmogorov time and length scales representing the energy dissipative eddies are expressed by Tk = CkT (υ/ε)1/2 and lk = Ckl (υ3/ε)1/4, respectively. The available DNS data for fully developed channel flows with and without wall injection / suction are used to determine the coefficients. It is found that, with the typical values of CtT = Ctl = 1 which are usually adopted in the turbulence study, CkT = 2 and Ckl = 3. However, this set of coefficients lead to underprediction of the thickness of viscous sublayer yVSL+. By relaxing the usual assumption of CtT = Ctl = 1, a new set of coefficients: CtT = Ctl = 0.8, CkT = 4, and Ckl = 9 is suggested. The yVSL+ calculated with this set of coefficients becomes more physically reasonable.",
author = "Keh-Chin Chang and Jeng, {Shih Shiang}",
year = "2002",
month = "1",
day = "1",
doi = "10.1017/S172771910000410X",
language = "English",
volume = "18",
pages = "193--197",
journal = "Journal of Mechanics",
issn = "1727-7191",
publisher = "Cambridge University Press",
number = "4",

}

Coefficients of time and length scales of turbulent eddies. / Chang, Keh-Chin; Jeng, Shih Shiang.

In: Journal of Mechanics, Vol. 18, No. 4, 01.01.2002, p. 193-197.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Coefficients of time and length scales of turbulent eddies

AU - Chang, Keh-Chin

AU - Jeng, Shih Shiang

PY - 2002/1/1

Y1 - 2002/1/1

N2 - The turbulence time and length scales representing the energy containing eddies are by Tt = CtT k/ε and lt, = Ctl k32/ε, respectively, while the Kolmogorov time and length scales representing the energy dissipative eddies are expressed by Tk = CkT (υ/ε)1/2 and lk = Ckl (υ3/ε)1/4, respectively. The available DNS data for fully developed channel flows with and without wall injection / suction are used to determine the coefficients. It is found that, with the typical values of CtT = Ctl = 1 which are usually adopted in the turbulence study, CkT = 2 and Ckl = 3. However, this set of coefficients lead to underprediction of the thickness of viscous sublayer yVSL+. By relaxing the usual assumption of CtT = Ctl = 1, a new set of coefficients: CtT = Ctl = 0.8, CkT = 4, and Ckl = 9 is suggested. The yVSL+ calculated with this set of coefficients becomes more physically reasonable.

AB - The turbulence time and length scales representing the energy containing eddies are by Tt = CtT k/ε and lt, = Ctl k32/ε, respectively, while the Kolmogorov time and length scales representing the energy dissipative eddies are expressed by Tk = CkT (υ/ε)1/2 and lk = Ckl (υ3/ε)1/4, respectively. The available DNS data for fully developed channel flows with and without wall injection / suction are used to determine the coefficients. It is found that, with the typical values of CtT = Ctl = 1 which are usually adopted in the turbulence study, CkT = 2 and Ckl = 3. However, this set of coefficients lead to underprediction of the thickness of viscous sublayer yVSL+. By relaxing the usual assumption of CtT = Ctl = 1, a new set of coefficients: CtT = Ctl = 0.8, CkT = 4, and Ckl = 9 is suggested. The yVSL+ calculated with this set of coefficients becomes more physically reasonable.

UR - http://www.scopus.com/inward/record.url?scp=0037523417&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0037523417&partnerID=8YFLogxK

U2 - 10.1017/S172771910000410X

DO - 10.1017/S172771910000410X

M3 - Article

VL - 18

SP - 193

EP - 197

JO - Journal of Mechanics

JF - Journal of Mechanics

SN - 1727-7191

IS - 4

ER -