The hydrogen flow characteristics of the multistage hydrogen Knudsen compressor based on the thermal transpiration effect

Ye, Jianjun; Shao, Jiajia; Xie, Jing; Zhao, Zhiwei; Yu, Jia; Zhang, Yuan; Salem, Shehab

doi:10.1016/j.ijhydene.2019.04.155

Cited by 10 publications

(7 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The channels for all the KPs discussed above can be regarded as rectangular structures. The compression ratios achieved with other forms of micro-channel configurations proposed recently 94,116,[121][122][123][124][125][126][127][128][129][130][131][132][133][134][135] have already been reported in the corresponding numerical studies. Table 1 records the maximum compression ratios of different varieties of KPs in simulation studies.…”

Section: Pressure Characteristicsmentioning

confidence: 64%

“…Micro-channel structures in thermal creep flow KPs have rectangular channels (Fig. 10a) 116,[121][122][123][124][125][126][127][128] , curved-straight channels (Fig. 10b) [129][130][131][132] , double-curved channels (Fig.…”

Section: Thermal Creep Flow Kp Configurationmentioning

confidence: 99%

“…15b, we can see that the influence of the micro-channel geometric structure on pump pressure properties is obvious. For a rectangular channel, the compression ratio increases linearly with the stage number, manifesting the single-stage replication characteristic 127 . The simulation results have some differences from the experimental results 33,79 , which display an overall nonlinear variation.…”

Section: Pressure Characteristicsmentioning

confidence: 99%

“…In fact, the linear increase in compression ratio with stage number is only applicable to small stage number. However, enlarging the height or diameter of the connection channels can improve the compression ratio 127,189 . Additionally, in order to analyze the effect of surface roughness on the properties of KPs, micro-channel configurations with obstacles of different shapes (rectangle, triangle, semicircle) have been considered in the literature 190,191 .…”

Section: Pressure Characteristicsmentioning

confidence: 99%

See 3 more Smart Citations

Knudsen pumps: a review

Wang

Zhang

et al. 2020

Microsyst Nanoeng

View full text Add to dashboard Cite

The Knudsen pump (KP) is a kind of micro-pump that can form thermally induced flows induced by temperature fields in rarefied gas environments. It has the advantages of having no moving parts, simple structure, easy construction and extension, a wide range of energy sources, and low energy consumption. With the development of Micro/Nano Electro Mechanical Systems (MEMS/NEMS), extensive studies have been conducted on KPs, and the applications of KPs have widened. In order to obtain efficient flow fields in KPs, it is necessary to adopt modern computational methods for simulation and analysis. In many circumstances, the simulation and experimental results have good agreement. However, there seems to be no comprehensive review on KPs at present. In this paper, KPs are first defined and classified according to the flow mechanisms of the thermally induced flows. Then, the three aspects of configurations, performance, and applications of KPs in the current state of research are reviewed and analyzed. Finally, the current problems of KP are discussed, and some suggestions are provided for future research and applications.

show abstract

Section: Pressure Characteristicsmentioning

confidence: 64%

Section: Thermal Creep Flow Kp Configurationmentioning

confidence: 99%

Section: Pressure Characteristicsmentioning

confidence: 99%

Section: Pressure Characteristicsmentioning

confidence: 99%

See 2 more Smart Citations

Knudsen pumps: a review

Wang

Zhang

et al. 2020

Microsyst Nanoeng

View full text Add to dashboard Cite

show abstract

“…Many research groups have developed numerical models to estimate net flow that depends on the Knudsen number and flow coefficient [ 16 , 17 ]. Other aspects of the thermal transpiration pump have also been studied, such as different gases and multi-stage pumps [ 18 , 19 , 20 ] and modified governing equations of net flow were introduced and compared with experiments. More recently, flow characteristics and pumping mechanisms were studied by computational fluid dynamics [ 21 , 22 ] and different gases were studied using Direct Simulation Monte Carlo [ 23 , 24 ].…”

Section: Introductionmentioning

confidence: 99%

Performance Improvement of Glass Microfiber Based Thermal Transpiration Pump Using TPMS

et al. 2022

View full text Add to dashboard Cite

The Knudsen pump, known as a thermal transpiration membrane, is an air inducer that has been mostly studied for small-scale power generation devices. It is a porous medium that does not require any mechanically moving component, but rather uses the temperature gradient across two surfaces of the membrane to induce air from the colder side to the hotter side. If the temperature on the colder side of the membrane is reduced by a thermal guard, the pumping performance of the membrane seems to be improved. Therefore, the membrane integrating with TPMS structures as thermal guards for both experiment and simulation were conducted in this study. The results of flow rate and temperature distribution on the membrane surface were compared. Three characteristic parameters of the membrane, i.e., area factor, pore radius and permeability, were found and can be used in an equation to estimate the air flow rate through the membrane. Diamond was found to be the highest flow improvement while Primitive was the lowest flow improvement. The simulation results with varying %RD also supported that the contact area between the TPMS structure and the membrane inlet surface made Diamond conduct more heat out from the membrane surface than other TPMS structures.

show abstract