The numerical simulation of a ﬂow through a duct requires an externally speciﬁed forcing that makes the ﬂuid ﬂow against viscous friction. To this end, it is customary to enforce a constant value for either the ﬂow rate (CFR) or the pressure gradient (CPG). When comparing a laminar duct ﬂow before and after a geometrical modiﬁcation that induces a change of the viscous drag, both approaches lead to a change of the power input across the comparison. Similarly, when carrying out direct numerical simulation or large-eddy simulation of unsteady turbulent ﬂows, the power input is not constant over time. Carrying out a simulation at constant power input (CPI) is thus a further physically sound option, that becomes particularly appealing in the context of ﬂow control, where a comparison between control-on and control-off conditions has to be made. We describe how to carry out a CPI simulation, and start with deﬁning a new power-related Reynolds number, whose velocity scale is the bulk ﬂow that can be attained with a given pumping power in the laminar regime. Under the CPI condition, we derive a relation that is equivalent to the Fukagata–I ... mehr

Zugehörige Institution(en) am KIT |
Institut für Strömungsmechanik (ISTM) |

Publikationstyp |
Zeitschriftenaufsatz |

Jahr |
2014 |

Sprache |
Englisch |

Identifikator |
ISSN: 0022-1120 KITopen ID: 1000047788 |

Erschienen in |
Journal of Fluid Mechanics |

Band |
750 |

Seiten |
191-209 |

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