Despite almost 60 years of active research on jet noise, the noise generated by expulsion of hot gases at the exhaust of aircraft engines remains an important part of the total aircraft noise. This is particularly true in the case of supersonic aircrafts, where the high speed of the exhaust gases yields extremely high noise. In the framework of the development of future civil supersonic aircraf...

‎In this paper‎, ‎a matrix based method is considered for the solution of a class of nonlinear Volterra integral equations with a kernel of the general form $s^{beta}(t-s)^{-alpha}G(y(s))$ based on the Tau method‎. ‎In this method‎, ‎a transformation of the independent variable is first introduced in order to obtain a new equation with smoother solution‎. ‎Error analysis of this method is also ...

Inviscid computations are presented of a self-propelled virtual body connected to combined heaving and pitching foil that uses continuous intermittent motions. It is determined swimming can improve efficiency when the dimensionless heave ratio $h^* < 0.7$ while it degrades for \geq 0.7$. This consequence physical origins force production pitch-dominated ($h^* 0.5$) heave-dominated > Based on in...

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...

We study the derivation of macroscopic traffic models from car-following vehicle dynamics by means hydrodynamic limits an Enskog-type kinetic description. consider superposition Follow-the-Leader (FTL) interactions and relaxation towards a traffic-dependent Optimal Velocity (OV) we show that resulting depend on relative frequency between these two microscopic processes. If FTL dominate then one...

A LL jets have noise generation due to turbulent mixing; such mixing leads to the production of Reynolds stresses, the source term within the Lighthill acoustic analogy [1]. In addition to this source, a jet that possesses coherent, large-scale structures that travel with velocities exceeding the local speed of sound will emit Mach wave radiation, a highly efficient noise production mechanism. ...

We consider unsteady undular bores for a pair of coupled equations of Boussinesq-type which contain the familiar fully nonlinear dissipationless shallow-water dynamics and the leading-order fully nonlinear dispersive terms. This system contains one horizontal space dimension and time and can be systematically derived from the full Euler equations for irrotational flows with a free surface using...

The Lighthill–Panton and Lyman–Huggins interpretations of vorticity dynamics are extended to the enstrophy. There exist two competing definitions current tensor, which describes flow rate in fluid interior, corresponding boundary flux, represents local creation on a boundary. It is demonstrated that each definition tensor leads consistent set for enstrophy current, flux dissipation term. This a...

Advanced monitoring and control of arterial road traffic network operations requires accurate knowledge of current and predicted performance measures on the network. Recently studied signal control algorithms, for example, use the lengths of vehicle queues for each turning movement to determine how subsequent signal cycles should be distributed into phases. This article presents 5 a queue estim...