Material Surface Emissivity Mapping During Transient Cooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for determining the area distribution of emissivity on material surfaces are inefficient due to the need for lengthy stabilization times in stationary heating processes, leading to inhomogeneous heating and inaccuracies in emissivity measurement, particularly when access to the backside of the material is limited or previous thermal processes affect heating absorption.
Innovation Solution
A non-contact heating method using a transient, non-stationary thermal process during the cooling phase after heating, measuring the area distribution of emitted heat flux to determine emissivity, ensuring homogeneous surface temperature through heat flux measurement during cooling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If stationary heating processes are used to achieve homogeneous surface temperature, then temperature homogeneity is improved, but measurement time increases significantly
Solution Approach 1:
The patent applies dynamic heating by using a moving heat source (laser) that scans across the material surface in a predetermined pattern, rather than using stationary heating. This dynamic approach allows the system to achieve homogeneous temperature distribution across the measurement area without requiring prolonged stabilization time, as the continuous movement of the heat source distributes thermal energy more efficiently and rapidly throughout the target area.
Solution Approach 2:
The patent implements periodic heating cycles where the laser heat source repeatedly scans across the material surface in controlled patterns. These periodic actions allow the material to reach thermal equilibrium more quickly through repeated heating-cooling cycles, reducing the overall time required to achieve homogeneous temperature compared to continuous stationary heating.
2Productivity
If contact heating methods are used to transfer heat directly, then heating efficiency is improved, but temperature inhomogeneity increases due to contact variations
Solution Approach 1:
The patent replaces contact-based mechanical heating with non-contact optical heating using a laser heat source. This substitution eliminates the issues of contact inhomogeneity and thermal resistance variations that occur with physical contact methods. The laser delivers thermal energy directly to the material surface through electromagnetic radiation, ensuring uniform and controllable heating without the drawbacks of mechanical contact variations.
3Power
If heating acts on the front side of the material, then direct heating is achieved, but inhomogeneous heating occurs due to varying absorption
Solution Approach 1:
The patent applies preliminary heating to areas surrounding the measurement region before actually measuring emissivity in the target area. This preliminary action ensures that the entire material surface, including the measurement area, reaches a homogeneous temperature state before measurements begin. By pre-heating the surrounding areas, the system compensates for potential temperature gradients and ensures uniform thermal conditions across the entire measurement field.
4Stability of the object's composition
If the entire scanned area is heated homogeneously, then temperature uniformity is improved, but heating complexity increases
Solution Approach 1:
The patent divides the heating process into segments by using a moving laser heat source that scans across the material surface in a predetermined pattern rather than heating the entire area simultaneously. This segmentation of the heating process allows for controlled, sequential heating of different regions, achieving overall temperature uniformity while keeping the heating system itself relatively simple and avoiding the complexity of multi-element heating arrays.
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 approach significantly reduces measurement time and ensures spatially homogeneous heating, improving repeatability and simplifying automation by avoiding areas affected by previous processes, allowing for efficient quality control in thermal processes.
Implementation Method 1
A non-contact heating method using a transient, non-stationary thermal process during the cooling phase after heating
Implementation Method 2
measuring the area distribution of the measured heat flux emitted by material surface at the measured area
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Method of measuring the area distribution of emissivity of a material surface The background of the invention is that the heated area of the material is heated by a non-contact heating heat flux and after the heating is completed the area distribution of radiation heat flux emitted by measured area of material surface is measured at a predetermined time of area temperature homogenization and at the emissivity evaluation area in the cooling phase during the nonstationary cooling process and in the individual places of the emissivity evaluation area, the emissivity is determined by calculation.