Phononic Surface Structure for Passive Turbulent Drag Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing flow control methods struggle to effectively manage turbulent drag, laminar-to-turbulent transition, and turbulence in fluid flows due to the complexity of frequency, phase, and orientation variations, and they often require active control devices that consume excessive energy and are not suitable for intense environments.
Innovation Solution
The use of phononic crystals and locally resonant metamaterials as subsurfaces that interact with fluid flows to alter wave phases and amplitudes, inducing destructive interference and stabilizing or destabilizing the flow as needed, without active control devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If active control devices are used to manage flow behavior, then flow control effectiveness is improved, but energy consumption increases and device complexity increases
Solution Approach 1:
The compliant surface structure passively interacts with flow disturbances through its inherent elastic properties, eliminating the need for external energy sources or active control systems. The surface automatically responds to flow conditions through its compliance, achieving flow control without self-service energy consumption
Solution Approach 2:
The patent replaces active mechanical control devices with a passive compliant surface that uses elastic deformation and wave propagation mechanisms. This substitution eliminates complex mechanical actuators, sensors, and control systems while maintaining flow control functionality through material compliance
2Adaptability or versatility
If compliant surface is used to interact with flow, then flow control capability is improved, but surface instability increases
Solution Approach 1:
The patent optimizes the compliance parameter of the surface to achieve a balance between flow control capability and stability. By carefully selecting material properties and structural characteristics, the surface provides sufficient compliance for flow interaction while maintaining structural integrity and avoiding excessive instability or flutter
Solution Approach 2:
The compliant surface provides just enough compliance to effectively interact with flow disturbances without exceeding the threshold that would cause harmful instabilities. The compliance is tuned to be sufficient for flow control but not excessive to the point of causing surface flutter or structural failure
3Stability of the object's composition
If wave cancellation is used to stabilize flow, then flow stability is improved, but control complexity increases
Solution Approach 1:
The compliant surface automatically achieves wave cancellation through its passive elastic response to flow disturbances. The surface inherently generates counter-waves through its deformation, eliminating the need for complex active control systems that would be required to coordinate multiple actuators for wave cancellation
Solution Approach 2:
The compliant surface acts as an intermediary between the flow field and the structure, mediating the interaction through elastic deformation. This intermediary mechanism naturally produces wave cancellation effects without requiring direct complex control of multiple components
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces skin friction drag, delays laminar-to-turbulent transition, enhances or attenuates turbulence, and controls heat transfer by passively modifying flow characteristics, offering energy-efficient and stable flow management.
Implementation Method 1
The subsurface feature comprises a phononic crystal or locally resonant metamaterial adapted to receive the at least one wave having the at least one frequency based upon the pressure from the flow via the interface surface and alter the phase of the at least one wave
Data Source
Figure 1A
Figure 1B~1E
Figure 1F
AI summary
A phononic material and a method of using a phononic material for use in interacting with a fluid or solid flow are provided. The phononic material includes an interface surface and a subsurface feature. The interface surface is adapted to move in response to a pressure associated with at least one wave in a flow exerted on the interface surface. The subsurface feature extends from the interface surface. The subsurface feature comprises a phononic crystal or locally resonant metamaterial adapted to receive the at least one wave having the at least one frequency based upon the pressure from the flow via the interface surface and alter the phase of the at least one wave. The interface surface is adapted to vibrate at a frequency, phase and amplitude in response to the manipulated/altered phase of the at least one wave.