Self-Aligned Digital Projection Schlieren System
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing focusing schlieren systems require significant time and effort to switch between configurations due to the need for precise alignment and fabrication of separate source and cutoff grids, which can become warped and suffer from optical aberrations, limiting their application to lower-speed flows.
Innovation Solution
A digital projection focusing schlieren system that uses a single grid element, such as an LCD, back-illuminated by a light source to project a source grid onto a retroreflective background, eliminating the need for a separate cutoff grid and allowing for self-alignment and off-axis measurements, while reducing glare and reflections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate source grid and cutoff grid are used in focusing schlieren system, then measurement precision can be maintained, but setup time and alignment effort increase significantly
Solution Approach 1:
The patent combines the source grid and cutoff grid into a single grid element that performs both functions. The grid is positioned at the focal plane of the imaging lens, where it serves as both the light source modulation element and the reference pattern for schlieren detection, eliminating the need for separate grids and their complex alignment procedures.
Solution Approach 2:
The single grid element is designed to perform multiple functions simultaneously: it acts as the source grid to modulate light, serves as the cutoff grid for schlieren detection, and provides a reference pattern for image processing. This multi-functional design eliminates the need for separate dedicated components for each function.
2Reliability
If separate source grid and cutoff grid are used, then optical path can be established, but alignment precision requirements increase and cause measurement errors
Solution Approach 1:
By merging the source and cutoff grids into a single element positioned at the focal plane, the patent eliminates the alignment interface between two separate grids. The single grid self-aligns to the optical path through its focal plane position, removing the need for precise relative alignment between multiple components.
3Adaptability or versatility
If traditional focusing schlieren system is used, then flow visualization can be achieved, but system complexity increases with multiple grids and alignment requirements
Solution Approach 1:
The patent reduces system complexity by combining multiple grid components into a single grid element. This simplification maintains the flow visualization capability while eliminating the complex configuration and alignment procedures previously required for separate source and cutoff grids.
Solution Approach 2:
The single grid element at the focal plane serves itself by automatically establishing the correct optical relationships. The grid's position at the focal plane inherently provides the correct spacing and orientation for both source modulation and schlieren detection, eliminating the need for external alignment adjustments.
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 solution significantly reduces setup and adjustment time, enables faster switching between configurations, and allows for higher-speed flow measurements by eliminating the need for precise alignment and optical aberration correction, while also providing flexibility in sensitivity direction and simultaneous measurement capabilities.
Implementation Method 1
a light source back-illuminates a grid element to project an image of a source grid
Implementation Method 2
The projected source grid image is then re-imaged onto the original grid element at a slight offset
Data Source
AI summary
A digital projection and reflected glare reduction system according to various aspects of the present technology may include a digital display device capable of generating a one or two dimensional source grid pattern back-illuminated by a light source to project an image of a source grid onto a retroreflective background. The projected source grid image may then be re-imaged onto the original grid element at a slight offset eliminating the need to generate a separate cutoff grid thereby reducing the amount of time required to setup and adjust the system. The digital display device is also capable of switching between a schlieren visualization capability to some other visualization capability (such as particle tracking velocimetry (PTV), particle imaging velocimetry (NV), temperature sensitive paint measurements (TSP), pressure sensitive paint measurements (PSP), photogrammetry, etc.) allowing for the simultaneous use of two different imaging techniques.