Laboratory experiments were carried out for study the change in wavelength, frequency and amplitude of regular low-amplitude gravity capillary waves in the range 2 to 5 Hz in a slow sinusoidal current with a velocity amplitude up to 10 to 15 cm/sec. The experiments were made in a glass flume measuring 670 x 20 x 40 cm. A nonstationary uniform current was simulated by movement of a measurement carriage (on which a wave generator and sensors were mounted) along rails. Three electrode sensors were situated at a distance of 5, 20 and 25 cm from the wave generator. The accuracy in determining frequency and amplitude was 10 and 20% respectively; the accuracy in measuring wavelength was 10%. The generation of a current, changing with tiem, resulted in a change in all the parameters of the waves. Data are given for two ranges of current velocities: 10 to 15 cm/sec and 20 to 30 cm/sec. All the observations fit well within the framework of a linear kinematic model. A control experiment with a motionless carriage and a countercurrent slowly changing with time confirmed the legitimacy of transfer of the data obtained with the carriage moving relative to calm water to the case of a uniform nonstationary current.
USSR Report Earth Sciences JPRS UES
- Pub Date:
- June 1985
- Gravity Waves;
- Sine Waves;
- Fluid Mechanics and Heat Transfer