Article
Thermodynamics
C. F. Camarotti, J. W. Hartwig, J. N. Chung
Summary: The bubble point pressure (APBP) is the most crucial aspect in screen channel liquid acquisition device (LAD) design. Previous results have shown that using helium (GHe) pressurant can increase APBP values of cryogenic liquid nitrogen (LN2), while using gaseous nitrogen (GN2) pressurant can decrease APBP values. However, using warm pressurant always leads to a reduction in APBP regardless of the pressurant gas type. This study found a degradation in GHe APBP but no degradation in GN2 APBP at elevated pressurant bulk gas temperatures (TGB), contradicting historical trends.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
C. F. Camarotti, J. W. Hartwig, J. N. Chung
Summary: Screen channel liquid acquisition devices (LADs) are essential for future deep space travel to ensure vapor-free delivery of propellants. This paper presents cryogenic liquid nitrogen (LN2) screen channel LAD bubble point experiments and investigates the effect of pressurant gas type on LAD performance.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2022)
Article
Chemistry, Physical
Jian Li, Yanzhong Li, Yuan Ma, Lei Wang, Fushou Xie
Summary: This paper investigates the crucial role of the screen channel liquid acquisition device in the in-orbit management of liquid propellant and proposes two innovative suggestions for optimizing its design.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Thermodynamics
Jian Li, Yanzhong Li, Yuan Ma, Lei Wang, Fushou Xie
Summary: This study focuses on the bubble point pressure (BPP) of Dutch Twill weave (DTW) screens for gas-liquid separation. The two-stage-bubble-point pressure phenomenon was discovered in experiments, revealing the importance of three new parameters: the first order BPP, the second order BPP, and the critical depressurizing level. The microstructure of DTW screens was analyzed and a new conceptual model was proposed to explain the phenomenon. The mechanism was further quantitatively illustrated through CFD simulation. This discovery highlights the importance of reducing the driving pressure below the critical depressurizing level to fully restore the performance of the screen after a bubble breakthrough.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Chemistry, Physical
Pedro Henrique da Rosa Braun, Prithvi Shukla, Kurosch Rezwan, Michael Dreyer, Michaela Wilhelm
Summary: The development of porous ceramic screens with high chemical stability, low density, and thermal conductivity has the potential to become promising screen channel liquid acquisition devices (SC-LADs) for propellant management under microgravity conditions in the future. SiOC screens with aligned pores were fabricated using freeze-casting and applied as a SC-LAD. The pore window sizes and open porosity varied depending on the freezing temperature and the solid loading. The SC-LADs demonstrated high liquid removal capabilities but with variations in pressure drop and bubble ingestion, depending on the open porosity and pore window sizes of the screens.
Article
Engineering, Aerospace
Chase Camarotti, Jason Hartwig, David Yaegers, Siddhartha Vasireddy, Jacob Chung
Summary: In the microgravity environment of space, liquid acquisition devices (LADs) are used to separate and control liquid and vapor phases of propellant. This study investigates the effect of different ramp rates on the compliance of LAD screens with rectangular geometries.
MICROGRAVITY SCIENCE AND TECHNOLOGY
(2022)
Article
Engineering, Aerospace
Siddhartha Vasireddy, Chase Camarotti, Jason Hartwig, J. N. Chung
Summary: Screen channel liquid acquisition devices (LADs) are used to separate liquid and vapor phases in space. This study experimentally measures the pressure difference and deflection thickness of the screen to calculate the compliance coefficient.
MICROGRAVITY SCIENCE AND TECHNOLOGY
(2022)
Article
Thermodynamics
David A. Yaegers, Jason W. Hartwig, Chase Camarotti, J. N. Chung
Summary: This paper presents new experimental data on the wicking rate of 12 screens with liquid nitrogen and validates a room temperature based model for cryogenic nitrogen. The results suggest that the room temperature model can be used to compute wicking velocities for most screen types.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
Thomas M. Conboy, Gregory W. Daines, Lucas E. O'Neill, Mark V. Zagarola, Jason W. Hartwig
Summary: Refueling spacecraft in orbit has the potential to increase payload capacity and reduce launch costs, but the challenge of acquiring vapor-free liquid propellants in microgravity conditions remains. Vane-type Propellant Management Devices (PMDs) excel in stabilizing and distributing liquid, while screen channel PMDs are less susceptible to gas ingestion and perform well at higher flow rates and adverse accelerations. To meet this need, Creare has developed a hybrid Liquid Acquisition Device (LAD) consisting of screened channels with guide vanes and a screened sump, providing a higher acquisition surface area per unit volume compared to existing designs.
Article
Chemistry, Analytical
Jian Li, Yuan Ma, Yanzhong Li, Bin Wang, Hui Zang
Summary: This study establishes a modified model to investigate the loss of outflow rate in screen channel liquid acquisition devices (LADs) when the screen is blocked by vapor. The research finds that the total area of the blocked screen primarily determines the loss of outflow rate, while the distribution of blockage position has negligible effects. Additionally, a characteristic curve is proposed to describe the LAD's robustness against blockage, showing the impact of different parameters.
Article
Chemistry, Physical
Lionel J. J. Catalan, Ebrahim Rezaei
Summary: Bubble reactors using molten metal alloys with strong catalytic activity are a promising technology for reducing the carbon intensity of hydrogen production. The hydrodynamics of bubble flow in molten metal plays an important role in reactor performance. A reactor model has been developed and validated with experimental data to optimize the design of multitubular catalytic bubble reactors. The optimization includes minimizing the total liquid metal volume to achieve high hydrogen production rates and methane conversions.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Multidisciplinary Sciences
Zheng Wang, Guang Yang, Ye Wang, Xin Jin, Rui Zhuan, Hao Zhang, Jingyi Wu
Summary: This study investigates the flow characteristics at the entrance region of screen channel liquid acquisition devices (LADs) and proposes a model that accounts for the three-dimensional flow field to predict the critical flow rate.
Article
Thermodynamics
Milad Ahmadi Khoshooei
Summary: Vapor pressure data and evaporation/sublimation rate of liquid samples are crucial parameters for designing new process units, requiring consideration of limitations and analysis precautions associated with traditional methods in order to obtain valuable data.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Thermodynamics
C. F. Camarotti, J. W. Hartwig, J. N. Chung
Summary: The LAD screen allows liquid to flow while blocking vapor by utilizing surface tension forces in microgravity. This study analyzes the effects of noncondensable pressurization and autogenous pressurization on the temperature gradient in the liquid side boundary layer near the screen during APBP tests. Experimental data is provided for the liquid screen side temperature at varying distances from the screen using different dewar pressures in cryogenic conditions. An empirical correlation is developed to correct APBP data based on the temperature gradient.
APPLIED THERMAL ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Q. Yang, J. Liu, C. Zhou, J. Ni, E. I. Vovk, Y. Yang, B. Yang, X. Guan
Summary: Dry reforming of methane (CH4) with carbon dioxide (CO2) using a combination of electrolysis and thermocatalysis in a liquid alloy-salt system achieves effective and stable catalytic performance under relatively mild operation conditions, showing promising potential for application.
MATERIALS TODAY CHEMISTRY
(2022)
