Jets are one of the most fascinating topics in fluid mechanics. For aeronautics, turbulent jet-noise modelling is particularly challenging, not only because of the poor understanding of high Reynolds number turbulence, but also because of the extremely low acoustic efficiency of high-speed jets. Turbulent jet-noise models starting from the classical Lighthill acoustic analogy to state-of-the ar...

This paper proposes a new method that makes the direct volume integration of Lighthill stress term in FWH acoustic analogy affordable terms both computational time and disk storage requirement. The is based on dual mesh concept, i.e. while fine used CFD, relatively coarse for calculation. being independent observer positions integral formula are calculated CFD mapped onto during simulation. The...

Acoustic holes are the hydrodynamic analog of standard black holes. Featuring an acoustic horizon, these systems spontaneously emit phonons at Hawking temperature. We derive temperature horizon by fully exploiting analogy between and within a covariant kinetic theory approach. After deriving phonon distribution function from equations, we reproduce expression equating entropy energy losses gain...

analogy and how to treat it is among the earliest issues in the jurisprudence and principles of legal schools. meanwhile, although in shī‘ism the universal approach in this respect has since long ago been a negative one and it still continues to be so, the important issue that has to be taken into further consideration and more deeply contemplated on despite the theological viewpoints of the ju...

The optical dispersive prism is a well-studied element, which allows separating white light into its constituent spectral colors, and stands in nature as water droplets. In analogy to this definition, the acoustic dispersive prism should be an acoustic device with capability of splitting a broadband acoustic wave into its constituent Fourier components. However, due to the acoustical nature of ...

Controlling the angular momentum of spins with very short external perturbations is a key issue in modern magnetism. For example it allows manipulating the magnetization for recording purposes or for inducing high frequency spin torque oscillations. Towards that purpose it is essential to modify and control the angular momentum of the magnetization which precesses around the resultant effective...