Analysis of a kite anemometer
Abstract
Equations of motion for a rigid, tailless kite and tether system are derived from free body diagrams. A direct, analytical solution of these equations provides tether tension in a steady wind. Numerical solutions of linearized equations of motion provide the kite tether tension in a transient, turbulent wind field. A similar analysis is applied to a kite-tail-tether system. The results of these analyses show that line tension at the ground anchor is within a few percent of tether tension at the kite. Wind shear does not significantly affect line tension. Thus the tethered kite anemometer can measure height-dependent wind fields based on steady-state, uniform wind calibrations. Unsteady winds also have an insignificant effect on the tether if gust amplitude and frequency are such that tether accelerations are below 9.8m/s(2). In a variable wind, tether tension is in phase with wind variations. Tension amplitude is dependent on the magnitude and frequency of wind variations.
- Publication:
-
Final Report FWG Associates
- Pub Date:
- December 1981
- Bibcode:
- 1981fwga.rept.....H
- Keywords:
-
- Anemometers;
- Equations Of Motion;
- Numerical Analysis;
- Speed Indicators;
- Tethered Balloons;
- Wind Velocity Measurement;
- Analysis (Mathematics);
- Measuring Instruments;
- Partial Differential Equations;
- Wind Measurement;
- Instrumentation and Photography