Full-parametric three-dimensional modeling method for elbow-shaped draft tube

Abstract

The invention relates to the technical field of three-dimensional digital model construction, and discloses an elbow-shaped draft tube full-parametric three-dimensional modeling method, which comprises the following steps of: establishing a draft tube input shaft system and a section single-line diagram component, outputting a section single-line outline, eight extreme points and a central point,fitting the central points of all the single-line diagrams to generate a central axis, correspondingly coupling and lofting two adjacent single-line diagrams according to extreme point numbers by taking the central axis of the draft tube as a ridge line, establishing a segmented entity component, and outputting segmented entities by taking the two adjacent single-line diagrams and the central axisof the draft tube as input elements, and subjecting all the segmented entities to Boolean combination operation to generate a draft tube overall entity model. According to the elbow-shaped draft tubefull-parameterization three-dimensional modeling method, the design table containing section positioning and section size parameters serves as input, and the elbow-shaped draft tube full-parameterization three-dimensional model is rapidly established and can be dynamically modified.

Description

technical field [0001] The invention relates to the technical field of model construction, in particular to a fully parametric three-dimensional modeling method for an elbow-shaped draft tube. Background technique [0002] The elbow-shaped draft tube of the powerhouse of the hydropower station is an important flow-passing part of the reaction turbine. Its structure is a large-span cavity shaped body with complex shapes and complex forces. Its size and shape largely affect the investment in the civil engineering of the lower part of the hydropower station. And the efficiency and stability of turbine operation. [0003] The shape of the elbow-shaped draft tube of the powerhouse is obtained from hydraulic experiments, and the coordinates and dimensions of the shape are used as the main control parameters. Due to the high precision requirements for the design and construction of the elbow-shaped draft tube, a high-precision 3D model with full parameters is established for optimi...

AI Technical Summary

Problems solved by technology

At present, the design and modeling of the elbow-shaped draft tube of the factory building is limited to a simplified segmented model. This design and modeling method is relatively complicated, the accuracy cannot be guaranteed, and the modification is cumbersome. Every time the model is modified, it must be re-established.

Some are based on single line Figure 1 Create section profiles one by one, and use multi-section lofting to build model surfaces and entities. This method has a better degree of parameterization, but when building a 3D draft tube model, it is still necessary to manually establish the coupling relationship of the geometric nodes of the one-line diagram. There are many steps. When the coupling relationship changes due to changes in the nodes of two adjacent one-line diagrams, errors will occur in the surfaces and solids generated by lofting according to the original coupling relationship, making structural optimization unable to proceed smoothly, and the role of the 3D model is limited.

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