Conical Flow Meter Insert Fatigue Life
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Mechanical structures in flow meters, such as cone-shaped inserts, are prone to fatigue failures due to stress concentrations at welds and abrupt geometry changes, which can lead to vibrations-induced mechanical failures, compromising the longevity of the measurement devices without significantly affecting the microwave resonant frequency measurements.
Innovation Solution
The cone and support fins are fabricated as a single piece with integrated support fins and a stress relief radius, eliminating welds in high-stress areas and distributing stress more evenly, while maintaining the microwave resonator's properties by minimizing the extension of support fins along the conical portion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the cone and support fins are fabricated as separate pieces requiring welding, then the assembly process is simpler, but stress concentrations at welds lead to fatigue failures
Solution Approach 1:
The cone and support fins are fabricated as a single integral piece rather than separate components requiring welding. This merging eliminates weld joints and associated stress concentrations, directly resolving the contradiction by prioritizing fatigue life while maintaining manufacturability through single-piece fabrication processes
2Strength
If the support fins extend further along the conical portion, then the structural strength increases, but the microwave measurement quality deteriorates
Solution Approach 1:
The support fins are designed with varying dimensions along their length, with the width and thickness changing to optimize both structural strength and electromagnetic performance. This local variation in geometry allows the fins to provide adequate mechanical support while minimizing interference with microwave measurements in the critical measurement region
3Ease of manufacture
If abrupt geometry changes are present in the insert structure, then the manufacturing process is simpler, but stress concentrations increase leading to fatigue failures
Solution Approach 1:
The insert structure incorporates curved transitions and rounded corners instead of abrupt geometry changes. This curvature eliminates stress concentration points that would lead to fatigue failures, while the curved geometries can still be manufactured using standard processes, resolving the contradiction between manufacturing simplicity and fatigue resistance
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 design enhances the fatigue life of the insert and support structure without affecting the microwave measurement quality, reducing the risk of vibration-induced failures and extending the service life of the flow meter components.
Implementation Method 1
The gap between the body and the wall constitutes an electromagnetic resonator. At least one coupling probe is positioned close to the gap. The method comprises the steps of applying an electromagnetic signal and monitoring the frequency response of the resonator through the probe
Implementation Method 2
The insert creates turbulence in the flow, which tends to mix or homogenize the flow
Implementation Method 3
The insert is also a restriction to the flow, which causes the flow to accelerate, due to the reduced cross sectional area, as it passes the insert. The acceleration causes the pressure to drop, and thus creates a differential pressure over the insert. This differential pressure is proportional to the flow speed and density, thus providing a means to measure the flow
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
Insert for electromagnetic resonance measurements, having a substantially unsupported essentially conically or biconically shaped portion and a support structure including at least one fin extending from the insert to a conduit wall or meter body. The at least one fin extends partly into the essentially conically or biconically shaped portion, but only to an extent that does not influence substantially on the electromagnetic resonance measurement. A system including such insert is also described.