Lectures on Experimental Aerodynamics
Lectures on Experimental Aerodynamics
The lectures attempt to provide an overview of image-based aerodynamics measurement techniques and their applications for students and researchers. The presented materials include the research results obtained by the 澳门六合彩官网直播 group and collaborators in other institutions.
The following topics are included.
- Pressure and temperature sensitive paints (PSP and TSP),
- Physics-based optical flow method for extraction of velocity fields from flow visualization images,
- Global skin-friction diagnostics based on surface flow visualizations with luminescent oil, sublimation coating, TSP and PSP,
- Photogrammetry/videogrammetry for measurements of static and dynamic model deformation and attitudes,
- Relevant topics including skin-friction topology, avian wing geometry and kinematics, comparative scaling of fixed and flapping flyers, wing flow control, and oil droplet deposition in turbulent flow.
Pressure Temperature Sensitive Paints
Outline
- Historical remarks on PSP/TSP
- Foundations of PSP/TSP
- Intensity-based measurement and uncertainty analysis based on PSP system modeling
- Lifetime-based measurement and uncertainty
- Photogrammertry and integration with PSP/TSP
- Applications of PSP/TSP
- Conclusions
Fluid Flow and Optical Flow
Objective -
To develop a general theoretical framework for extracting velocity fields from various flow visualization images
- Projected motion equation and optical flow equation
- Variational formulation and Euler-Lagrange equations
- Numerical algorithms
- Application to various flow visualizations
Extraction of Skin Friction Fields from Surface Flow Visualizations as an Inverse Problem
Objective -
To extract high-resolution skin friction fields from surface flow visualization images by using a unified approach of optical flow
- Global luminescent oil-film (GLOF) visualization
- Surface heat transfer visualization with TSP
- Surface mass transfer visualization with PSP and sublimating coatings in air and dye in water
Skin Friction Topology in a Region Enclosed by Penetrable Boundaries
Objectives -
- To obtain high-resolution skin friction fields in regions with penetrable boundaries on surface in complex 3D separated flows
- To examine the skin friction topology by application of the Poincare-Bendixson index formula
Global Skin Friction Diagnostics Using Temperature Sensitive Paint
Objective -
To explore the feasibility of global skin friction diagnostic based on surface temperature measurement using temperature sensitive paint (TSP)
Current State -
- Skin friction is the most difficult surface quantity to measure in aerodynamics and fluid mechanics
- Global skin friction diagnostic is highly desirable in studies of complex flows
Global Skin Friction Diagnostics Based on Surface Mass-Transfer Visualizations
Objective -
To explore the feasibility of global skin friction diagnostic based on surface mass-transfer visualizations
Current State -
- Global luminescent oil-film skin friction meter
- Global skin friction diagnostics based on surface heat-transfer/temperature visualizations
Skin Friction Topology of Wing-Body Junction Flows
Objectives -
- To obtain high-resolution skin friction fields in wing-body junction flows from luminescent oil-film images taken at multiple viewing angles and positions
- To examine the skin friction topology of wing-body junction flows based on the topological rules
Skin Friction Fields on Delta Wings
Objective -
To map skin friction fields on a 65藲 Delta wing and a 76/40藲 double-Delta wing using a global luminescent oil skin friction meter
Skin Friction Fields and Surface Dye Patterns on Delta Wings in Water Flows
Objective -
To extract high-resolution skin friction fields from surface luminescent dye visualizations in water flows
Skin Friction Structures Extracted from Surface Pressure Gradient Field
Objective -
To study the feasibility of extracting skin friction structures from surface pressure gradient field
Flow Structures Extracted from Visualization Images: Vector Fields and Topology
Comparison between Optical Flow and Cross-Correlation Methods for Extraction of Velocity Fields from Particle Images
Objective -
To quantitatively compare the optical flow method and cross-correlation method in extraction of velocity vectors from particle images
Temperature Sensitive Paint Heat Flux Measurements in Hypersonic Tunnels
Objective -
To develop data-reduction methods and algorithms for the determination of heat flux fields from transient temperature sensitive paint (TSP) measurements in hypersonic tunnels particularly in the Purdue Mach-6 Quiet Ludwieg Tube
Videogrammetric Technique for Aerospace Applications: From Model Attitude and Deformation to Surface Geometry
Objectives -
- Measurement of attitudes and positions of models and control surface
- Measurement of static and dynamic aeroelastic deformation and extracting vibration modes
- Mapping surface qualities onto surface
- Reconstruction of 3D velocity fields
Thin Wing Vibration Control Using Flexible Fins
Objective -
Study thin wing vibration control using flexible fins based on high-speed videogrammetry and PIV measurements
Effects of Flexible Fin on Low-Frequency Oscillation in Post-Stalled Flows
Objectives-
- Develop a simple passive device to suppress the natural low-frequency oscillation and reduce drag in deep stall
- Explore the physical mechanisms
Avian Wing Geometry and Kinematics
Objectives -
- Recover avian wing geometry from non-contact laser scanning surface measurements
- Extract avian wing kinematics from videos of flying birds
- Give analytical expressions for avian wing geometry and kinematics for computational and experimental studies
Comparative Scaling of Birds and Aircraft
Fluid Mechanics of Deposition of Micron Liquid Droplets on Wall in Impinging Turbulent Air Jet
Objectives -
To understand the physical mechanisms of micron oil droplet deposition in an impinging turbulent jet based on measurements and theoretical analysis
- Flow structures and formation of droplet deposition ring patterns
- Droplet collisions induced by small-scale turbulence
Determining Aerodynamic Loads Based on Optical Deformation Measurements
Objective -
To develop an optical technique for remote, non-contact measurement of aerodynamic loads
Videogrammetric Determination of Aircraft Position and Attitude for Vision-Based Autonomous Landing
Objectives -
- To study videogrammetric methods for vision-based landing based on natural ground features
- To develop algorithms for virtual reality simulation and real flight control system
- To evaluate the accuracy of videogrammetric methods
Flight Testing: Measurements and Design
What is Flight Testing?
- Flight testing is the process of gathering information (or data) which will accurately describe the capabilities of a particular type of airplane, and which can be used to accurately predict and optimize the use of all airplanes of that same type in future missions.
- Flight testing of research airplanes constitutes the gathering of data in regions of the flight environment where little past information has been obtained. This information is then used to design future airplanes that can operate safely in this new environment.
- Flight testing is at the end of the aircraft design process and is a unique part of it.
Image-Based Aerodynamics Measurements - Transfer from Aerospace to Automotive Applications
Objective -
To develop unified global high-resolution flow diagnostics tools for automotive and aerospace applications
Computer Vision and Measurements in Aerospace Applications
Objective -
To build a unified theoretical framework for quantitative image-based measurements of morphology and motion fields of deformable bodies like fluids
- Geometric Structures: Points, Curves, Surfaces
- Motion Fields: Points, Curves, Surfaces (Geometric Flow) Complex Continuous Patterns
Skin Friction Measurements Using Elastic Films
Data Processing Tools for Dynamic Pressure-Sensitive Paint
Development of Pressure-Sensitive Paint Systems for Low-Speed Flows and Large Wind Tunnels
Analytical Inverse Heat Inverse Method for Temperature-Sensitive Coating Measurement on a Finite Base
Objective -
To develop analytical inverse method and algorithms for the determination of heat flux fields on a finite base from transient temperature-sensitive-coating measurements