Blades play a very important role in aviation and land power plants, and their quality will directly affect the aerodynamic performance of blades. At the same time, the blade is also one of the most complex parts in the machinery manufacturing industry, due to the special shape of the blade, the space angle and size parameters are many, and the technical requirements are also very strict. Therefore, the inspection of the blade is very important.
There are many types and quantities of blades on aero engines. According to the structure of the engine, the blades are divided into compressor blades and turbine blades, according to the working conditions, they are divided into high-pressure blades and low-pressure blades, and according to the working state, they are divided into rotor blades (also known as working blades) and stator blades (also known as rectifier and guide vanes). In the different processing stages of the blade, the contents that need to be inspected are complex and varied, such as blade shape, cross-section thickness, blade bending, cross-section torsion, chord length and roar size, etc.
The ZEISS INSPECT Airfoil (ZIA) software covers all parameters of blade inspection with simple operation and beautiful reporting. And the software is continuously iteratively updated every year to continuously meet the most advanced testing requirements and improve the speed of detection and analysis.
This article will explain some of the updates and upgrades in the ZIA 2023 version. The main content includes the following five aspects:
New feature 1: Faster calculation of mid-arc lines
The large number of measured points on the blade cross-section affects the calculation speed of the middle arc, and many subsequent characteristics are related to the middle arc.
In the ZIA 2023 version, the calculation speed of the mid-arc has been increased, especially for the leaf-shaped cross-section with a high density of actual measurement points, the calculation of the mid-arc can be completed in less than 1 second.
New feature 2: Improve the stability of the medium arc algorithm
The actual point distribution of the front and rear edges of the blade shape will affect the calculation of the middle arc, especially when the front and back edges of the blade shape have radius compensation problems or other problems due to the deviation of the actual blade length, and there are knots or other errors, the center arc will not be calculated.
In the ZIA 2023 version, the calculation method of the middle arc has been improved, especially for abnormal cross-section profiles, and the middle arc can be calculated stably and accurately.
New function 3: Added the function of leaf shape arc and thickness distribution detection
According to the NACA standard, there are a series of key geometric characteristics regarding the overall shape curvature or thickness distribution percentage. These features are crucial for both the design and reverse engineering of the blade shape.
In the ZIA 2023 release, the blade arc and thickness distribution detection function is added, and the distance distribution graph can be generated based on the percentage of the reference profile length.
New feature 4: Added best fit for CMM Data
As shown in the figure, the black arrows represent the "nominal normal direction of the section". Suppose you want to measure a curve, and the blue ball is the probe. (Note that the measurement direction is probed in the opposite direction to the surface normal of the workpiece), and the yellow arrow is the "Nominal Normal Direction of the Surface". Therefore, it can be seen that the "nominal normal direction of the cross-section" and the "nominal normal direction of the surface" are inconsistent.
In the ZIA 2023 release, a more accurate calculation of shape error is provided for CMM data, which includes: the best fit is calculated as "nominal to actual", and the shape deviation is calculated along the "surface nominal normal direction".
This results are more accurate when calculating shape deviations and are easier to benchmark against other blade measurement software on the market.
New feature 5: For Gaussian best fit, the option "Consider Point Distribution" has been added
In previous versions, the best fit for the shape and position of the leaf shape was to perform the fitting calculations for the entire leaf shape independently of the measured point density. This means that even if the point density in a particular area of the leaf cross-section is relatively high, the calculation weight will not be higher.
However, for CMM data, there is actually another case for fitting the weights of the point density distribution (because in most cases, considering the importance of the front and rear edges of the leaf shape and the difficulty of measurement, more points will be allocated when using CMM measurement to ensure the accuracy of the measurement results).
In the ZIA 2023 release, the "Consider Point Distribution" box has been added for Gaussian best fit. According to the calculation of the weight fitting of the point density distribution, the larger the area of the point density, the greater the influence on the results, that is, when fitting, the deviation of the area with high point density is minimized.