The development of deep learning has inspired some new methods to solve the 3D reconstruction problem for Tomographic Particle Image Velocimetry (Tomo-PIV). However, the supervised learning method requires a large num...
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The development of deep learning has inspired some new methods to solve the 3D reconstruction problem for Tomographic Particle Image Velocimetry (Tomo-PIV). However, the supervised learning method requires a large number of data with ground truth as training information, which is very difficult to gather from experiments. Although synthetic datasets can be used as alternatives, they are still not exactly the same with the real-world experimental data. In this paper, an Unsupervised Reconstruction Technique based on U-net (UnRTU) is proposed to reconstruct volume particle distribution explicitly. Instead of using ground truth data, a projection function is used as an unsupervised loss function for network training to reconstruct particle distribution. The UnRTU was compared with some traditional algebraic reconstruction algorithms and supervised learning method using synthetic data under different particle density and noise level. The results indicate that UnRTU outperforms these traditional approaches in both reconstruction quality and noise robustness, and is comparable to the supervised learning methods AI-PR. For experimental tests, particles dispersed in cured epoxy resin are moved by an electric rail with a certain speed to obtain the ground truth data of particle velocity. Compared with other algorithms, the reconstructed particle distribution by UnRTU has the best reconstruction fidelity. And the accuracy of the 3D velocity field estimated by UnRTU is 12.9% higher than that from the traditional MLOS-MART algorithm. It demonstrates significant potential and advantages for UnRTU in 3D reconstruction of particle distribution. Finally, UnRTU was successfully applied to the high-speed planar cascade airflow field, demonstrating its applicability for measuring complex fluid flow fields at higher particle density.
In the concept of Fluoride-Salt-cooled high-Temperature Advanced Reactor (FuSTAR), the Printed Circuit Heat Exchanger (PCHE) is mainly considered in its supercritical carbon dioxide (S–CO2) Brayton cycle secondary lo...
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As a coolant enabling the reactor with a high efficiency and low volume, the supercritical CO2 has becoming a hot topic nowadays. However, the fuel rod behaviors under accidents are not studied thoroughly, especially ...
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Loss of Coolant Accident (LOCA) is one of the major design-basis accidents in LWRs. Fuel rod may fail due to the rupture of the cladding. By developing a LOCA simulation module, the steady-state fuel rod performance a...
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Improving boiling heat transfer in thin liquid films by employing external electrical fields and macro-structured surfaces presents promising for tackling the growing difficulties related to high-heat-flux thermal man...
Improving boiling heat transfer in thin liquid films by employing external electrical fields and macro-structured surfaces presents promising for tackling the growing difficulties related to high-heat-flux thermal management in electronic devices. In this study, six distinct macro-structured surfaces are designed and fabricated to gain insight into how liquid film thickness, structural parameters, and applied voltage affect the efficiency of boiling heat transfer with ethanol as the coolant. High-speed imaging and precise heat transfer measurements are employed to characterize the boiling performance, providing insights into the underlying fundamentals driving the observed enhancements. Results reveal that applying a 4-kV voltage increases departure frequency of bubble by 86 % and a 28 % reduction in diameter, causing a 20 % improvement in critical heat flux (CHF). CHF is positively correlated with liquid film thickness and pin height, but negatively with pin spacing, achieving a 139 % increase under optimal conditions. Liquid film thickness was found to have the most significant impact on CHF, followed by pin spacing and applied voltage. By simplifying the void fraction equation, a new CHF correlation is proposed that introduces a dimensionless characteristic length, representing the relative effects between bubble size and film thickness, while accounting for the synergy between the electric field and surface macro-structure.
Plate fuel elements is gradually used in advanced reactor structure design because of its advantages of high fuel consumption and high safety. The flow channel of the plate fuel element is a typical rectangular narrow...
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The Molten Salt Reactor (MSR) can meet the demand of transmutation and breeding. In this study, theoretical calculation of steady thermal hydraulic characteristics of a graphite-moderated channel type MSR is conducted...
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The Molten Salt Reactor (MSR) can meet the demand of transmutation and breeding. In this study, theoretical calculation of steady thermal hydraulic characteristics of a graphite-moderated channel type MSR is conducted. The DRAGON code is adopted to calculate the axial and radial power factor firstly. The flow and heat transfer model in the fuel salt and graphite are developed on basis of the fundamental mass, momentum and energy equations. The results show the detailed flow distribution in the core, and the temperature profiles of the fuel salt, inner and outer wall in the nine typical elements along the axial flow direction are also obtained.
In the combined system of lead cooled fast reactor (LFR) and supercritical carbon dioxide (S-CO2) Brayton cycle, the intermediate heat exchanger plays a key role in the whole power system. However, the existing heat e...
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Converting solar energy into hydrogen(H_(2))by photocatalytic water splitting is a promising approach to simultaneously address the increasing energy demand and environmental *** decade has passed since the discovery ...
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Converting solar energy into hydrogen(H_(2))by photocatalytic water splitting is a promising approach to simultaneously address the increasing energy demand and environmental *** decade has passed since the discovery of photo-induced water splitting phenomenon on TiO_(2)photoanode,while the solar to H_(2) efficiency is still around 1%,far below the least industrial ***,developing efficient photocatalyst with a high energy conversion efficiency is still one of the main tasks to be *** carbon nitride(g-C_(3)N_(4))is just such an emerging and potential ***,in this review,the state-of-the-art advances in g-C_(3)N_(4)based photocatalysts for overall water splitting were summarized in three sections according to the strategies used,and future challenges and new directions were discussed.
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