Coefficients of time and length scales of turbulent eddies

Keh Chin Chang; Shih Shiang Jeng

doi:10.1017/S172771910000410X

Coefficients of time and length scales of turbulent eddies

Keh Chin Chang, Shih Shiang Jeng

Department of Aeronautics and Astronautics

Research output: Contribution to journal › Article › peer-review

1 Citation (Scopus)

Abstract

The turbulence time and length scales representing the energy containing eddies are by T_t = C_t^T k/ε and l_t, = C_t^l k³²/ε, respectively, while the Kolmogorov time and length scales representing the energy dissipative eddies are expressed by T_k = C_k^T (υ/ε)^1/2 and l_k = C_k^l (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 C_t^T = C_t^l = 1 which are usually adopted in the turbulence study, C_k^T = 2 and C_k^l = 3. However, this set of coefficients lead to underprediction of the thickness of viscous sublayer y^VSL+. By relaxing the usual assumption of C_t^T = C_t^l = 1, a new set of coefficients: C_t^T = C_t^l = 0.8, C_k^T = 4, and C_k^l = 9 is suggested. The y_VSL⁺ calculated with this set of coefficients becomes more physically reasonable.

Original language	English
Pages (from-to)	193-197
Number of pages	5
Journal	Journal of Mechanics
Volume	18
Issue number	4
DOIs	https://doi.org/10.1017/S172771910000410X
Publication status	Published - 2002

All Science Journal Classification (ASJC) codes

Condensed Matter Physics
Mechanical Engineering
Applied Mathematics

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10.1017/S172771910000410X

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@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 = "Chang, {Keh Chin} and Jeng, {Shih Shiang}",

note = "Funding Information: The authors gratefully acknowledge the grant support from the National Science Council of the Republic of China under the contract NSC89-2212-E006-032.",

year = "2002",

doi = "10.1017/S172771910000410X",

language = "English",

volume = "18",

pages = "193--197",

journal = "Journal of Mechanics",

issn = "1727-7191",

publisher = "Cambridge University Press",

number = "4",

}

TY - JOUR

T1 - Coefficients of time and length scales of turbulent eddies

AU - Chang, Keh Chin

AU - Jeng, Shih Shiang

N1 - Funding Information: The authors gratefully acknowledge the grant support from the National Science Council of the Republic of China under the contract NSC89-2212-E006-032.

PY - 2002

Y1 - 2002

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.

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U2 - 10.1017/S172771910000410X

DO - 10.1017/S172771910000410X

M3 - Article

AN - SCOPUS:0037523417

SN - 1727-7191

VL - 18

SP - 193

EP - 197

JO - Journal of Mechanics

JF - Journal of Mechanics

IS - 4

ER -

Coefficients of time and length scales of turbulent eddies

Abstract

All Science Journal Classification (ASJC) codes

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