https://nova.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:47182 k and 𝜀_θ, respectively, the mean dissipation rates of turbulent kinetic energy k and half the temperature variance ⟨𝜃²⟩/2, is developed for slightly heated turbulent flows of air. It is limited to a Prandtl number near unity and applicable to flows where temperature can be treated as a passive scalar. A significant advantage of the method is that 𝜀_k and 𝜀_θ can both be estimated from the measurement of a temperature frequency spectrum, G_θθ(f). The method relies on the collapse in the dissipative range of one-dimensional temperature spectra, ϕ_θ(k₁η), when normalized with 𝜀_θ, 𝜀_k, and ν. This collapse ensues from a similarity analysis of scale-by-scale budgets of the second-order structure function for the temperature. A generic spectrum 𝜙_𝜃𝐺(𝑘₁𝜂), defined in the wavenumber range 0.07 ≤ k₁η ≤ 0.7, is used to construct a spectral chart. The method has been tested in several flows and found to be reliable. In particular, it is tested on the axis of a slightly heated round jet, where 𝜀_k and 𝜀_θ can be estimated accurately via the budgets of k and ⟨𝜃²⟩/2, and the agreement between these estimates and the spectral chart results is almost perfect.]]> Wed 14 Dec 2022 15:55:53 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:25544 Tue 16 Oct 2018 12:08:02 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:52749 Thu 26 Oct 2023 09:18:46 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:5137 0.2. Similar results were also observed for second-order structure functions (not shown) for Kolmogorov normalised radius r* < 10. Although, the quality of collapsed is poorer for transverse component, the result highlights that Kolmogorov similarity hypothesis is reasonably well satisfied. However, the suction results shows a significant departure from the no suction case of the Kolmogorov normalised spectra and second-order structure functions for k₁* < 0.2 and r* > 20, respectively. The departure at the larger scales with collapse at the small scales suggests that suction induce a change in the small-scale motion. This is also reflected in the alteration of mean turbulent energy dissipation rate and Taylor microscale Reynolds number. This change is a result of the weakening of the large-scale structures. The effect is increased as the suction rate is increased.]]> Sat 24 Mar 2018 07:49:39 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:30353 Sat 24 Mar 2018 07:40:24 AEDT ]]>