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Wave drag due to generation of capillary-gravity surface waves
Teodor Burghelea1, Victor Steinberg
1Department of Physics of Complex Systems, The Weizmann Institute of Science, Rehovot 76100, Israel.
Summary
Wave resistance occurs when objects move faster than a minimum surface wave velocity, similar to Cherenkov radiation. This study reveals a continuous transition to wave drag, contradicting existing theories.
Area of Science:
- Fluid dynamics
- Surface physics
- Wave mechanics
Background:
- Objects moving on fluid surfaces generate capillary-gravity waves.
- Surface wave generation is analogous to roton generation in superfluid helium via Cherenkov radiation.
Purpose of the Study:
- Investigate the onset of wave resistance in fluids.
- Examine the relationship between object velocity and wave generation.
- Compare experimental findings with theoretical predictions.
Main Methods:
- Experimental investigation of wave resistance using various fluids and object sizes.
- Theoretical analysis of capillary-gravity wave patterns and wave generation regions.
- Comparison of experimental data with theoretical models.
Main Results:
- Wave resistance onset occurs above a minimum phase velocity (V(c)).
- The transition to wave drag is continuous, with force proportional to sqrt[V-V(c)].
- Reduced wave drag force data from different fluids and object sizes collapse onto a single curve.
- Experimental and theoretical analyses of wave patterns show good agreement.
Conclusions:
- The study provides experimental evidence for Cherenkov radiation-like wave generation.
- Observed continuous transition contradicts Raphaël and de Gennes theory.
- A universal scaling law for reduced wave drag force is established.
- Theoretical and experimental wave pattern analyses are consistent.