Deformable Surface Wall Coupling for Active Boundary-Layer Drag Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing technologies fail to effectively control surface drag in various fluid flow scenarios, leading to inefficiencies in speed and fuel consumption across different transportation modes and systems, as they rely on passive aerodynamic shapes rather than active manipulation of the boundary layer.
Innovation Solution
A fluid control system that employs a deformable surface with deformers or movable sections, controlled by sensors and actuators, to actively modify the boundary layer by creating spanwise and streamwise motions, thereby controlling surface drag by manipulating turbulent flow regimes and velocity gradients.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If passive aerodynamic shapes are used, then the system structure is simple, but surface drag cannot be effectively controlled leading to poor fuel efficiency
Solution Approach 1:
The patent applies the dynamics principle by transitioning from static passive aerodynamic shapes to active dynamic surface deformation. The deformable surface can change its configuration in real-time to adapt to different flow conditions, enabling effective drag control across varying Reynolds numbers while maintaining reasonable system complexity through targeted actuation zones
Solution Approach 2:
The patent implements parameter changes by modifying the physical state and configuration of the surface through deformation. By changing surface geometry parameters (curvature, angle, position) in response to flow conditions, the system achieves improved fuel efficiency without requiring complete structural redesign
2Reliability
If active control systems are implemented, then surface drag control is improved, but the system complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the deformable surface into multiple independently controllable zones or actuators. This allows selective actuation of specific surface regions based on local flow conditions, improving drag control reliability while reducing overall system complexity compared to full-surface actuation
Solution Approach 2:
The patent uses an intermediary approach by introducing a deformable surface layer between the rigid body structure and the fluid flow. This intermediary element absorbs and transmits control actions effectively, achieving reliable drag control while isolating the complexity of the control mechanism from the main structure
3Adaptability or versatility
If fixed aerodynamic shapes are used, then manufacturing is simple, but adaptability to different flow conditions is poor
Solution Approach 1:
The patent implements dynamics by creating surfaces that can actively change their aerodynamic properties in response to different flow conditions. The deformable surface allows the same structure to adapt to varying Reynolds numbers and flow regimes, achieving versatility without requiring multiple fixed configurations
Solution Approach 2:
The patent applies universality by designing a deformable surface system that can perform multiple aerodynamic functions across different operating conditions. The same actuation mechanism serves to control drag, delay separation, and adapt to various Reynolds numbers, reducing the need for condition-specific 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
Enables real-time adaptable control of surface drag, reducing energy consumption and improving performance across a wide range of Reynolds numbers, from high-speed maritime shipping to low-speed unmanned aerial vehicles, by actively managing turbulent motions and boundary layer turbulence.
Implementation Method 1
modify a boundary layer of a fluid that is flowing over the deformable surface by selectively deforming the top side of the surface
Implementation Method 2
controlling surface drag by manipulating turbulent flow regimes and velocity gradients
Implementation Method 3
at least one deformer between the deformable surface and the body. The at least one deformer is configured to modify a boundary layer of a fluid that is flowing over the deformable surface by selectively deforming the top side of the surface
Implementation Method 4
using a sensor to measure a parameter of a fluid flowing over a surface
Implementation Method 5
a controller that causes the actuator to cause the surface to move with a movement parameter corresponding to a flow parameter of at least one of the first turbulent flow regime or the second turbulent flow regime
Data Source
AI summary
A system includes a surface having a fluid flowing over the surface. The fluid includes a flow regime having a streamwise length scale greater than about 100 times η and less than about 100,000 times η, where η is a viscous length scale of the flow regime, and a convective time scale greater than about 10η′ and less than about 10,000η′, where η′ is a viscous time scale of the flow regime. The system includes a controller that causes at least one of motion the surface to modify fluid flow in the flow regime based on the streamwise length scale and the convective time scale or motion of the flow regime based on the streamwise length scale and the convective time scale.