Resolution is an
important index for evaluating the reconstruction
performance of temperature distributions in a combustion environment,
and a higher resolution is necessary to obtain more precise combustion
diagnoses. Tunable diode laser absorption tomography (TDLAT) has proven
to be a powerful combustion diagnosis method for efficient detection.
However, restricted by the line-of-sight (LOS) measurement, the reconstruction
resolution of TDLAT was dependent on the size of the detection data,
which made it difficult to obtain sufficient data for extreme environmental
measurements. This severely limits the development of TDLAT in combustion
diagnosis. To overcome this limitation, we proposed a super-resolution
reconstruction method based on the super-resolution residual U-Net
(SRResUNet) to improve the reconstruction resolution using a software
method that could take full advantage of residual networks and U-Net
to extract the deep features from the limited data of TDLAT to reconstruct
the temperature distribution efficiently. A simulation study was conducted
to investigate how the parameters would affect the performance of
the super-resolution model and to optimize the reconstruction. The
results show that our SRResUNet model can effectively improve the
accuracy of reconstruction with super-resolution, with good antinoise
performance, with the errors of 2-, 4-, and 8-times super-resolution
reconstructions of approximately 5.3, 7.4, and 9.7%, respectively.
The successful demonstration of SRResUNet in this work indicates the
possible applications of other deep learning methods, such as enhanced
super-resolution generative adversarial networks (ESRGANs) for limited-data
TDLAT.