초록 ▼

A probe (P) capable of sensing acoustic and hydrodynamic pressures in a heated flow field and an associated apparatus for acoustically exciting the heat flow (35), for positioning the probe (P) within the flow field and fro acquiring data. The probe (P) consists of a miniature microphone (10) mounte

A probe (P) capable of sensing acoustic and hydrodynamic pressures in a heated flow field and an associated apparatus for acoustically exciting the heat flow (35), for positioning the probe (P) within the flow field and fro acquiring data. The probe (P) consists of a miniature microphone (10) mounted in an assembly which provides direct water cooling to the microphone body and which, by means of a bullet nosed extension (23, 24) with lateral ports (25), protects the microphone element (10) from direct impingement of the flow (35). Acoustic excitation of the flow (35) is introduced upstream of the nozzle (34) through a tube (37) from an externally mounted acoustic driver (36) which responds to the amplified output of a signal generator (38); the signal generator (38) and the amplifier (39) are adjusted to control the frequency and amplitude of the excitation. A traversing mechanism (32), capable of movement in three orthogonal directions is used to position the probe (P) within the flow (35). Signals from an acoustic excitation sensor (47) and from the probe (P) are amplified to convenient levels and processed by a two-channel Fast Fourier analyzer (40) which produces the transfer function correlograms and spectra of the input signal individually and jointly displayed on a recorder/indicator (41).

대표청구항 ▼

An apparatus for measuring fluctuating hydrodynamic pressures in a high temperature flowing medium comprising: a signal generator operative in said medium to alter the magnitude and frequency of the coherent large-scale turbulence within said medium; at least one pressure transducer; a support conne

An apparatus for measuring fluctuating hydrodynamic pressures in a high temperature flowing medium comprising: a signal generator operative in said medium to alter the magnitude and frequency of the coherent large-scale turbulence within said medium; at least one pressure transducer; a support connected to each said transducer whereby each said transducer is mounted in a predetermined position in said medium downstream of said altered turbulence: a power supply to excite each said transducer whereby signals corresponding to the altered turbulence aforesaid are detected; an analyzer operatively connected between said signal generator and each said transducer to receive and compare the signals therefrom; and an indicator connected to the output side of said analyzer to display the results thereof