Accounting for flow intermittency in environmental flows design

Accounting for environmental flow requirements in global water assessments

As the water requirement for food production and other human needs grows, quantification of environmental flow requirements (EFRs) is necessary to assess the amount of water needed to sustain freshwater ecosystems. EFRs are the result of the quantification of water necessary to sustain the riverine ecosystem, which is calculated from the mean of an environmental flow (EF) method. In this study,...

Intermittency in spiral Poiseuille flow

The results of an experimental study on intermittent spiral vortices observed in a counter-rotating Taylor-Couette system with an additional axial through flow, i.e. SpiralPoiseuille flow, are presented. Convectively unstable upstream propagating spiral vortices appear in the laminar basic flow from an oscillatory instability and in general become absolutely unstable at higher inner cylinder Re...

Accounting for Values in Design

Passive scalar intermittency in low temperature helium flows.

We report new measurements of mixing of passive temperature field in a turbulent flow. The use of low temperature helium gas allows us to span a range of microscale Reynolds number, R(lambda), from 100 to 650. The exponents xi(n) of the temperature structure functions approximately r(xi(n)) are shown to saturate to xi(infinity) approximately 1.45+/-0...

Possible Effects of Small-Scale Intermittency in Turbulent Reacting Flows

It is now well established that quantities such as energy dissipation, scalar dissipation and enstrophy possess huge fluctuations in turbulent flows, and that the fluctuations become increasingly stronger with increasing Reynolds number of the flow. The effects of this small-scale “intermittency” on various aspects of reacting flows have not been addressed fully. This paper draws brief attentio...