- Title
- Effects of low Reynolds number on decay exponent in grid turbulence
- Creator
- Kamruzzaman, Md; Djenidi, L.; Antonia, R. A.
- Publisher Link
- http://dx.doi.org/10th International Conference on Mechanical Engineering (ICME2013). Procedia Engineering, Volume 90 (Dhakar, Bangladesh 20-22 December, 2013) p. 327-332
- Publisher Link
- http://dx.doi.org/10.1016/j.proeng.2014.11.857
- Publisher
- Elsevier
- Resource Type
- conference paper
- Date
- 2014
- Description
- This present work is to investigate on the decay exponent (n) of decay power law (q'2~(t-to)n, q'20 is the virtual origin) at low Reynolds numbers based on Taylor microscale Rλ(≡ u'λ/v) ≤ 64. Hot wire measurements are carried out in a grid turbulence subjected to a 1.36:1 contraction. The grid consists in large square holes (mesh size 43.75 mm and solidity 43%); small square holes (mesh size 14.15 mm and solidity 43%) and woven mesh grid (mesh size 5 mm and solidity 36%). The decay exponent (n) is determined using three different methods: (i) decay of q'2, (ii) transport equation for ɛ, the mean dissipation of the turbulent kinetic energy and (iii) λ method (Taylor microscale λ ≡ √5〈q'2〉/〈ɛd〉 angular bracket denotes the ensemble). Preliminary results indicate that the magnitude n increases while Rλ(≡ u'λ/v) decreases, in accordance with the turbulence theory.
- Subject
- initial conditions; turbulent kinetic energy; mean dissipation energy rate; Taylor microscale; Taylor microscale Reynolds number; decay exponent
- Identifier
- http://hdl.handle.net/1959.13/1062082
- Identifier
- uon:17035
- Language
- eng
- Full Text
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