Graphite-Insert Pitot Tube Assembly for Ice-Resistant Strength
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing pitot tubes used in aircraft are often structurally weak and prone to ice buildup, which impairs their aerodynamic efficiency and performance.
Innovation Solution
A process involving hot iso-static processing (HIPping) and laser metal deposition, combined with additive manufacturing techniques, is used to create a pitot tube assembly with a graphite insert, providing a transition fit and constraining motion to enhance structural strength and prevent ice accumulation, while machining forms aerodynamic profiles and drain holes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional manufacturing methods are used for pitot tubes, then manufacturing simplicity is maintained, but structural strength is insufficient and ice buildup occurs
Solution Approach 1:
The patent employs a composite structure consisting of a nickel alloy tube (providing structural strength) and a graphite insert (providing icephobic properties and thermal conductivity). This composite design resolves the contradiction by combining materials with complementary properties to achieve both high strength and ice resistance, which neither material could provide alone.
Solution Approach 2:
The graphite insert is nested within the nickel alloy tube, creating a layered composite structure. This nesting approach allows the integration of two different materials with distinct functions (structural support from the outer tube, ice prevention from the inner graphite layer) without requiring complex assembly processes, thus maintaining manufacturing simplicity while achieving superior performance.
2Reliability
If a graphite insert is embedded in a nickel alloy tube, then thermal conductivity and structural integrity improve, but manufacturing process complexity increases
Solution Approach 1:
The graphite insert is prepared and positioned within the nickel alloy tube before the final welding and sealing operations. This preliminary positioning ensures proper alignment and fit of the composite components, facilitating subsequent manufacturing steps and reducing the complexity of final assembly operations.
Solution Approach 2:
The patent introduces intermediate manufacturing steps including HIPping (Hot Isostatic Pressing) and heat treatment processes that act as mediators to bond the graphite insert to the nickel alloy tube. These intermediate processes ensure strong interfacial bonding and structural integrity while maintaining control over the manufacturing complexity through standardized industrial processes.
3Temperature
If laser metal deposition and HIPping are used, then thermal conductivity and structural properties enhance, but manufacturing time and process complexity increase
Solution Approach 1:
The patent utilizes laser metal deposition to precisely control the thermal properties of the nickel alloy tube by varying deposition parameters such as laser power, scanning speed, and material feed rate. This allows optimization of thermal conductivity during the manufacturing process itself, rather than requiring separate post-processing steps, thereby reducing overall manufacturing time.
Solution Approach 2:
The manufacturing process integrates laser metal deposition, HIPping, and heat treatment in a continuous sequence without interruption. The laser deposition prepares the surface and structure, immediately followed by HIPping to densify and bond the structure, and then heat treatment to finalize the thermal properties. This continuous workflow minimizes idle time and maximizes manufacturing efficiency.
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
The process results in a hybrid material pitot tube design that improves structural integrity, reduces ice buildup, and maintains aerodynamic efficiency by using a graphite insert within a nickel alloy tube, constrained by a sheath and endcap, with laser metal deposition and heat treatment enhancing thermal conductivity and structural properties.
Implementation Method 1
performing laser metal deposition to the assembly inlet portion and the assembly body portion
Implementation Method 2
performing hot iso-static processing (HIPping) or heat treating of the assembly after performing laser metal deposition
Data Source
Figure 1
Figure 2~5
Figure 6~7
AI summary
Disclosed is a process of manufacturing a pitot tube assembly (200) including: obtaining (10) a metal cylindrical tube (210) having a first axial portion (220) that is a first material blank for an assembly inlet portion (230) of the pitot tube assembly and a second axial portion (240) that is a second material blank for a body portion (250) of the pitot tube assembly; nesting (15) the first axial portion of the tube within a cylindrical graphite insert (260); nesting (20) the cylindrical graphite insert within a cylindrical sheath; constraining (25) axial motion of the insert; performing (30) laser scanning to the assembly inlet portion; and performing (35) additive manufacturing to the pitot tube assembly inlet portion.