A new instability mechanism is described in accretion flows where the gas is accelerated from a stationary shock to a sonic surface. The instability is based on a cycle of acoustic and entropic waves in this subsonic region of the flow. When advected adiabatically inward, entropy perturbations trigger acoustic waves propagating outward. If a shock is present at the outer boundary, acoustic wave...

Chao and Ruoff [*] have shown previously that by precompressing pyrophyllite prior to its use in high-pressure applications, one obtains a material which has a uniform density and uniform mechanical properties. We have recently studied the propagation of u trasonir nplIse~ in pyrnphyllit.p specimens to investigate the effect of specimen precompression on the.measured elastic moduli. Measurement...

A unique problem associated with the movements of a speed skating athlete inspired this practical work, looking into the question of using interactive auditory feedback to improve sporting movements and sporting movement acquisition. Presented here is a method for synchronizing the periodic movements of a subject against the movements of a model and sonifying that synchronization data in realti...

Transonic aerodynamics is the focus of strong interest at the present time because it is known to encompass one of the most efficient regimes of flight. While current transport aircraft operate just below the speed of sound, more radical aerodynamic designs, such as R. T. Jones’ proposal for a yawed wing in [1], favor operation at low supersonic speeds in the range from Mach 1 to 1.3 (a regime ...

By Frank Rinn INTRODUCTION Sonic measurements have been used for strength classification of utility poles since the 1960’s. Tapping with a hammer on one side of the pole induces a sound wave. A sensor at the other end of the pole detects when the stress wave arrives. The distance between tapping point and detector location is then divided by the measured time of flight, delivering a sonic speed...

The experimental study of air movement induced by natural ventilation in greenhouses requires a system to measure the air velocity "eld. A networked, two-dimensional sonic anemometer system was developed for simultaneous measurement of the instantaneous air speed and direction at 12 locations. The system performance was tested and validated against a mass #ow controller and a commercial, three-...

The swimbladder and associated sonic muscle of the Lusitanian toadfish Halobatrachus didactylus increase in size throughout life and are, respectively, 25% and 30% larger in type I (nest-holder) males than females, which may generate sexual differences in sound production. Sexual dimorphism in swimbladder is also evident in the morphological features of sonic muscle fibers. During the breeding ...

<p style='text-indent:20px;'>This paper focuses on two-dimensional continuous subsonic-sonic potential flows in a semi-infinitely long nozzle with straight lower wall and an upper which is convergent at the outlet while far fields. It proved that if variation rate of cross section suitably small, there exists unique such sonic curve intersects fixed point velocity flow along normal direct...

We describe the sound design and initial user study of an audio game created for gamers with visual impairments. Despite the wild popularity of platform games such as Super Mario [1] and the development of many audio games over the past decade, the platform genre has so far been all but ignored by audio game designers. To fill this gap and to add to the limited entertainment choices visually im...

We present a system that provides real-time audio feedback to athletes performing repetitive, periodic movements. The system synchronizes the temporal signal from a sensor placed on the athletes body with a model signal. The audio feedback tells the athlete how well they are synchronized with the model, and whether or not they are deviating from the model at critical points in the periodic moti...