Application of Hyperspectral Cameras in the Study of Atomization and Combustion of Boron-Based Nanofluid Fuels

I. Research Background and Testing Requirements

In the field of aerospace propulsion system research, boron-based high-energy nanofluid fuels, as a new type of high-energy-density fuel, have received widespread attention for their atomization and combustion characteristics. In the study of the ignition and combustion characteristics of B/JP-10 nanofluid fuels, the research team needed to test the spatial characteristic emission spectra of the fuel atomization combustion flame.

Traditional spectral testing methods struggle to obtain spectral information at different positions of the flame, whereas imaging hyperspectral cameras can simultaneously acquire the spatial and spectral information of the target, meeting the research requirements for spatial distribution analysis of flame components. The research team selected the FS-22 imaging hyperspectral camera produced by CHNSpec Technology Co., Ltd. to systematically test the spatial radiation spectra of the fuel atomization flame.

II. Testing Methods and Spectral Selection

During the research process, the FS-22 imaging hyperspectral camera was used in conjunction with a nanofluid fuel atomization combustion test system. This test system mainly consists of a sample feeding system, an atomization nozzle, a testing system, and a sampling system. An air atomization nozzle is used to atomize the boron-based nanofluid fuel, and a plasma arc is used to ignite the atomized jet of the sample.

The hyperspectral camera was used to collect spatial radiation spectral data of the fuel atomization flame. Based on the typical characteristic spectra of boron element and hydrocarbon fuel combustion, the research team selected two specific radiation bands for analysis:

1. 431 nm (blue band): corresponds to the radiation of CH radicals, used to characterize the combustion reaction of the hydrocarbon fuel JP-10.

2. 581 nm (green band): corresponds to the radiation of BO₂ radicals, used to characterize the combustion reaction of boron particles.

Figure 7.11   Radiative Density of 10 wt% B/JP-10 Nanofluid Fuel at 431 nm and 581 nm

By performing imaging analysis on the spatial distribution of radiation intensity in these two characteristic bands, researchers can distinguish the dominant reaction types at different positions within the atomized flame.

III. Experimental Results and Analysis

Spectral Analysis of Axial Center Position

Image data acquired by the hyperspectral camera shows that the spectral radiation at the axial center of the atomized torch exhibits obvious variation patterns. The spectral curves at Position 1 and Position 2 contain the characteristic "five-finger peaks" of boron combustion, and the radiation intensity increases with the distance from the nozzle, indicating that a boron combustion reaction exists at the center of the atomized torch from the nozzle to Position 2 and gradually strengthens with the movement of boron particles. From Position 3 to Position 5, the boron characteristic peaks at the center of the atomized flame disappear, indicating that no significant chemical reaction of boron particles occurs in this section.

Spectral Analysis of Radial Positions

Taking Position 4, where the axial center radiation intensity is highest, as the center, a comparative analysis of spectral radiation at different radial positions revealed: boron radiation characteristic peaks exist at both the upper and lower edges of the atomized torch, but the overall radiation intensity at the upper edge is slightly higher than that at the lower edge. This is because the JP-10 vapor moves upward under the influence of buoyancy, resulting in a larger amount of JP-10 participating in the reaction at the upper part of the torch. Simultaneously, distinct boron radiation characteristic peaks exist at the lower edge, which is consistent with the characteristic of boron moving downward under the influence of gravity.

Combustion Zone Division

Based on the spatial spectral radiation data acquired by the hyperspectral camera and combined with fuel atomization combustion images, the research team divided the center of the B/JP-10 nanofluid fuel atomization flame along the axial direction of the nozzle into four combustion zones: B/JP-10 coupled combustion zone (outlet section), JP-10 single-phase combustion zone (stable combustion section), B/JP-10 coupled combustion zone (tail flame section), and boron single-phase combustion zone. This regional division provides a basis for further understanding the fuel atomization combustion mechanism.

IV. Case Summary

The application of the CHNSpec FigSpec FS-22 hyperspectral camera in the research and development of boron-based high-energy nanofluid fuels has achieved the integrated collection of spatial and spectral information during the combustion process, solving the pain point where traditional detection methods struggle to cover the entire flame field and cannot simultaneously obtain component distributions. Its stable imaging performance and fine spectral resolution capabilities provide a reliable detection means for high-energy fuel formula optimization, combustion mechanism research, and combustion model establishment, assisting in technical breakthroughs for new types of aerospace propulsion fuels.

Product Recommendation: FigSpec FS-22 Imaging Hyperspectral Camera

• Image Resolution: 1920*1920
• Spectral Range: 400-1000nm
• Spectral Resolution (FWHM): 5nm
• Number of Spectral Channels: 600