Modelling of Liquid Hydrogen Boil-Off

In the paper

“While many studies [71][72][73][74][75][76][77][78][79][80][81][82][83][84] have investigated how to minimize boil-off losses and empirically determined that top fill (spray) is the most effective way to reduce transfer losses during loading, the underlying physics remains poorly understood.”

What the sources say

• ?Not checked — no full text of the sourcecites [71] Moran, M., and Nyland, T.E.D. (1992, January 6–8). Hydrogen no-vent testing in a 5 cubic foot (142 L) tank using spray nozzle and spray bar liquid injection. Proceedings of the 28th Joint Propulsion Conference and Exhibit: American Institute of Aeronautics and Astronautics, Nashville, TN, USA. source
• ?Not checked — no full text of the sourcecites [72] Moran, M.E., Nyland, T.W., and Driscoll, S.L. (1992). Hydrogen No-Vent Fill Testing in a 34 Liter (1.2 Cubic Foot) Tank. source
• Disputed

  The Conclusions (page unavailable) say that both the spray bar and bottom-orifice configurations maintained reasonable tank pressures and that there were few differences between their fills. Rather than finding spray fill most effective, the paper reports successful no-vent fills with both configurations; it also says its equilibrium model predicted both with good accuracy, while noting that low-gravity performance remained unproven. (LLM, conf=0.86)

  Checked by a reasoning model — may be wrong.

  cites [73] Chato, D. (1993, January 1). Ground testing for the no-vent fill of cryogenic tanks—Results of tests for a 71 cubic foot tank. Proceedings of the 29th Joint Propulsion Conference and Exhibit: American Institute of Aeronautics and Astronautics, Monterey, CA, USA. sourceExperimental — accuracy not yet measured

In the paper

“For Figure 4b, sensor TT10, located at the 61% fill level [78], was closest to the vapor liquid interface (approximately 13 cm below); the measured temperature was lower tha”

What the sources say

• Supported

  The citation in the printed sentence is attached to TT10’s location at the 61% fill level. Table 1 lists TT10 at that level, and Section 4.2 identifies Figure 4 as the 67% fill test. The citation is not attached to the later explanation about thermal stratification. (LLM, conf=0.92)

  cites [78] Swanger, 2017, Large scale production of densified hydrogen to the triple point and below, IOP Conf. Ser. Mater. Sci. Eng. source
• Partly supported

  Section 5 (page unavailable) reports liquid-temperature stratification and mentions TT10 in a 67% fill-level test. It does not identify TT10 as being at the 61% fill level or 13 cm below the interface, nor does it compare TT10’s measured temperature with an estimate or attribute such a difference to stratification. (LLM, conf=0.78)

  cites [75] Notardonato, 2017, Zero boil-off methods for large-scale liquid hydrogen tanks using integrated refrigeration and storage, IOP Conf. Ser. Mater. Sci. Eng. sourceExperimental — accuracy not yet measured

In the paper

“The mean effective thermal conductivity of this IRAS MLI system was 0.14 mW•m -1 •K -1 ; this value was used in Equation ( 14).”

What the sources say

• ?Could not verify

  The Conclusion (p. 18) reports effective thermal conductivities for MLI systems, but does not identify an IRAS MLI system or give its mean conductivity as 0.14 mW·m−1·K−1. Searches for “IRAS” and “0.14 mW/mK” found no passage establishing that value; the paper’s use of 0.00014 is in different units. Whether the citing authors used a value in their Equation (14) is not established by this source. (LLM, conf=0.76)

  cites [89] Fesmire, 2018, Cylindrical cryogenic calorimeter testing of six types of multilayer insulation systems, Cryogenics sourceExperimental — accuracy not yet measured

In the paper

“Recently [86], the model's performance was compared against BOG data obtained for ternary mixtures of methane, ethane, and nitrogen using our apparatus [58] and an LNG mixture used as rocket fuel conducted at Kennedy Space Centre (NASA) [87].”

What the sources say

• Supported

  The Abstract (page unavailable) reports BOG experiments on methane–ethane–nitrogen mixtures and an LNG mixture used as rocket fuel, then states that the data were compared with the SHV model. This supports the model-comparison claim attributed to [86]; the Kennedy Space Centre detail is separately cited to [87]. (LLM, conf=0.91)

  cites [86] Ghafri, 2021, Advanced Boil-Off Gas Studies of Liquefied Natural Gas used for the Space and Energy Industries, Acta Astronaut source
• ?Not checked — no full text of the sourcecites [58] Perez, 2021, Measurements of boil-off gas and stratification in cryogenic liquid nitrogen with implications for the storage and transport of liquefied natural gas, Energy source
• Partly supported

  The Introduction identifies a NASA Kennedy Space Center research program studying LNG as a potential rocket fuel. But the Discussion and future experimental investigations section says LNG had not yet been delivered and the first LNG boiloff test had not begun. This paper therefore does not provide the LNG boiloff data implied by the citation. (LLM, conf=0.90)

  cites [87] Rose, L., Swanger, A.M., Notardonato, W.U., Fesmire, J.E., Gleeson, J., and Carro, R. (2019, January 21–25). Integrated Refrigeration and Storage of LNG for Compositional Stability. Proceedings of the Cryogenic Engineering Conference and International Cryogenic Materials Conference, Hartford, CT, USA. sourceExperimental — accuracy not yet measured

In the paper

“This model is flexible with regards to the fluid type, utilises reference Helmholtz equations of state [60,61] for the thermodynamic property calculations and, most importantly, has physically-based parameters that are anchored by high-quality experimental data for pure fluids measured using a custom BOG apparatus.”

What the sources say

• ?Not checked — no full text of the sourcecites [60] Kunz, 2012, The GERG-2008 Wide-Range Equation of State for Natural Gases and Other Mixtures: An Expansion of GERG-2004, J. Chem. Eng. Data source
• Partly supported

  Split into 3 atoms — 2 confirmed, 1 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  cites [61] Monika, 2019, EOS-LNG: A Fundamental Equation of State for the Calculation of Thermodynamic Properties of Liquefied Natural Gases, J. Phys. Chem. Ref. Data sourceExperimental — accuracy not yet measured

In the paper

“This capability of the model to simulate storage at sub-atmospheric pressures is highly relevant to LH 2 applications in microgravity environments, including the cryogenic storage systems needed for future long-term space missions [90].”

What the sources say

• Partly supported

  The Background (page unavailable) says cryogenic-fluid storage in microgravity is crucial for future long-term space missions, and Future Work proposes comparing the model’s results with a cryogen in microgravity. Our copy does not establish that the model can simulate storage at sub-atmospheric pressures or specifically address LH2; the experiment used perfluoro-normal-pentane. (LLM, conf=0.84)

  cites [90] Tesny, E.M., and Hauser, D.M. (2019). Thermal Modeling of Zero Boil Off Tank Experiment. AIAA Propulsion and Energy 2019 Forum, American Institute of Aeronautics and Astronautics. sourceExperimental — accuracy not yet measured

In the paper

“The model exhibits excellent agreement with experimental and industrial data across a range of simulated conditions, including zero boil-off in microgravity environments, self-pressurization of a stored mass of LH 2 , and boil-off from a previously pressurized tank as it is being relieved of vapor.”

In the paper

“The model accounts for the heat transfer from the vapor to the liquid phase, incorporates realistic heat transfer mechanisms, and uses reference equations of state to calculate thermodynamic properties.”

In the paper

“The liquid temperature estimation closely aligns with the experimental results, except for an irregularity in the data occurring in the range of 125 to 250 h, which was caused by temporary issues with the refrigeration system.”

In the paper

“Overall, the BoilFAST calculations are in good agreement with the experimental dat for both the 33% (Figure 4a) and 67% (Figure 4b) fill experiments.”

In the paper

“The model is flexible with regards to the spin isomer composition of the hydrogen in each phase, tank geometry, and associated heat transfer, allowing the simulation of a wide range of scenarios.”

In the paper

“As a result, the sensor at a height of 139 cm is close to the liquid-vapor interface and is well represented by the model's liquid temperature estimation.”

In the paper

“A vaporliquid heat transfer coefficient, U VL = 1.04 W/m 2 /K, was chosen as this best”

In the paper

“Good agreement exists between the SHV model and each of the sources from all of the comparisons listed above.”

In the paper

“The model represent the pressurization and subsequent depressurization for both experiments, well onl slightly deviating in the pressurization rate during the initial heat leak and at the activa tion of the IRAS.”

In the paper

“The resulting simulation matched the experimental data well, capturing the variable heat ingress rate evident in the slightly non-linear experimental data.”

In the paper

“The resultant pressure decline in the tank is also well represented, with the same deviation observed in the middle of the experiment.”

In the paper

“At the initial tank pressure of 111 kPa, hydrogen has a saturation temperature of 20.6 K and para-hydrogen content of 99.8%.”

In the paper

“Liquid hydrogen (LH 2 ) [1][2][3] will play a key role in this transition [4] as it is clean-burning and can function as a store of energy generated from zero-or low-carbon sources, such as renewables or natural gas combined with carbon capture and storage.”

What the sources say

• ?Not checked — no full text of the sourcecites [4] Dong, 2018, CO2 emissions, economic and population growth, and renewable energy: Empirical evidence across regions, Energy Econ. source

In the paper

“The resulting temperature difference between the volume of stored liquid and the ambient environment ensures that heat ingress into the LH 2 is inevitable, which can cause it to evaporate [8].”

What the sources say

• ?Not checked — no full text of the sourcecites [8] Wang, 2021, Numerical investigation on subcooled pool film boiling of liquid hydrogen in different gravities, Int. J. Hydrogen Energy source

In the paper

“The evaporated vapor is termed boil-off gas (BOG) [9][10][11][12][13] and its generation leads to a pressure increase in the relevant storage tank in a process known as self-pressurization, necessitating venting of the tank into the atmosphere and loss of valuable hydrogen.”

What the sources say

• ?Not checked — no full text of the sourcecites [9] Tan, 2016, Enhancement of energy performance in a boil-off gas re-liquefaction system of LNG carriers using ejectors, Energy Convers. Manag. source
• ?Not checked — no full text of the sourcecites [10] Lin, 2018, An approach to estimating the boil-off rate of LNG in type C independent tank for floating storage and regasification unit under different filling ratio, Appl. Therm. Eng. source
• ?Not checked — no full text of the sourcecites [11] Querol, 2010, Boil off gas (BOG) management in Spanish liquid natural gas (LNG) terminals, Appl. Energy source

In the paper

“Additionally, heat ingress causes the vapor temperature to increase faster than that of the liquid due to the vapor's higher thermal diffusivity (α = κ/ρ•c p ), resulting in heat conduction across the vapor-liquid interface, and thus a temperature gradient in the top layer of the liquid phase with the interface at a higher temperature than the bulk liquid: this is known as thermal stratification [”

What the sources say

• ?Not checked — no full text of the sourcecites [15] Kang, 2018, Experimental investigation of thermal stratification in cryogenic tanks, Exp. Therm. Fluid Sci. source
• ?Not checked — no full text of the sourcecites [16] Gursu, 1993, Analysis and Optimization of Thermal Stratification and Self-Pressurization Effects in Liquid Hydrogen Storage Systems—Part 1: Model Development, J. Energy Resour. Technol. source
• ?Not checked — no full text of the sourcecites [17] Choi, 2017, Numerical analysis of convective flow and thermal stratification in a cryogenic storage tank, Numer. Heat Transf. Part A Appl. source

In the paper

“Depending on the insulation quality and the tank's surface-to-volume ratio, BOG generation can be on the order of 0.4% per day for a 50 m 3 cryogenic tank and 0.06% per day for a 20,000 m 3 LH 2 tank [14].”

What the sources say

• Not checked yetcites [14] Verfondern, K. (2007). Safety Considerations on Liquid Hydrogen, Forschungszentrum Jülich GmbH.

In the paper

“If the warmer stratified layers enter the rocket propellant feed system, pump cavitation can occur, which could potentially destroy the rocket [35].”

What the sources say

• ?Not checked — no full text of the sourcecites [35] Tatom, J.W., Brown, W.H., Knight, L.H., and Coxe, E.F. (1964). Analysis of Thermal Stratification of Liquid Hydrogen in Rocket Propellant Tanks, Springer. source

In the paper

“It was not possible to use existing correlations to estimate these values in this case as there are insufficient details concerning the insulation system used and uncertainly as to how the use of the electrical resistance heaters can be incorporated into such calculations.”

In the paper

“The liquid temperature estimated by the model is the saturation value corresponding to the tank pressure, which will always be higher than temperatures measured by sensors immersed in the bulk liquid phase (below the interface) due to stratification.”

In the paper

“An accurate and robust BOG model is thus required to model the storage of LH 2 in rockets and spacecraft, and thereby verify the performance of newly designed LH 2 storage systems.”

In the paper

“This was then expanded by Huerta and Vesovic [39] to include more realistic heat transfer mechanisms in the vapor phase.”

What the sources say

• ?Not checked — no full text of the sourcecites [39] Huerta, 2019, A realistic vapour phase heat transfer model for the weathering of LNG stored in large tanks, Energy source

In the paper

“The model calculations were also compared against literature data reported by the Gas Research Institute [56] for six different LNG weathering tests, and those reported by Harper and Powars [57] for a self-pressurization test from 283 kPa to 1585 kPa in an advanced on-vehicle LNG fuel system.”

What the sources say

• Not checked yetcites [56] Kountz, K.J. (1999). Weathering of On-Board Storage Tanks. Project Final Report, Institute of Gas Technology. IGT Project 32034-02.
• Not checked yetcites [57] Harper, G., and Powars, C. (2021, December 16). Advanced Liquid Natural Gas Onboard Storage System, Available online: https://www.osti.gov/biblio/835120-advanced-liquid-natural-gas-onboard-storage-system.

In the paper

“In our previous work modelling LNG boil-off [59], we found that a U VL of 4.0 W/m 2 /K produced the best match for the experiment.”

What the sources say

• ?Not checked — no full text of the sourcecites [59] Perez, 2021, Advanced Boil-Off Gas Studies for Liquefied Natural Gas, Appl. Therm. Eng. source

In the paper

“Both models consider heat ingress in the vapor and liquid phases separately and enable heat transfer between the two phases across the interfacial surface area.”

What the sources say

• ?Not checked — no full text of the sourcecites [44] Migliore, 2017, A non-equilibrium approach to modelling the weathering of stored Liquefied Natural Gas (LNG), Energy source
• ?Not checked — no full text of the sourcecites [39] Huerta, 2019, A realistic vapour phase heat transfer model for the weathering of LNG stored in large tanks, Energy source

In the paper

“Migliore et al. [44] developed a non-equilibrium numerical model that allows for the vapor phase to be at a higher temperature than the liquid phase.”

What the sources say

• ?Not checked — no full text of the sourcecites [44] Migliore, 2017, A non-equilibrium approach to modelling the weathering of stored Liquefied Natural Gas (LNG), Energy source

In the paper

“At absolute zero, all the hydrogen molecules must be in a rotational ground state and thus 100% para-hydrogen [65].”

What the sources say

• ?Not checked — no full text of the sourcecites [65] Boeva, 2017, Low-temperature ortho–para hydrogen conversion catalyzed by gold nanoparticles: Particle size does not affect the rate, Int. J. Hydrogen Energy source

In the paper

“The model has also been compared against the self-pressurization calculations reported by Wang et al. [46] for a horizontal storage tank, and the BOG calculations of Migliore et al. [44] for a standard LNG storage vertical tank with a 165,000 m 3 capacity.”

What the sources say

• ?Not checked — no full text of the sourcecites [46] Wang, 2020, Non-equilibrium thermodynamic model for liquefied natural gas storage tanks, Energy source
• ?Not checked — no full text of the sourcecites [44] Migliore, 2017, A non-equilibrium approach to modelling the weathering of stored Liquefied Natural Gas (LNG), Energy source

In the paper

“Tools that can accurately estimate BOG production are particularly important in the context of industrial-scale LH 2 storage, as the capital expense to design and implement such systems is large, and experimental testing at a relevant pilot-scale can be cost-prohibitive with the results obtained making it difficult to translate to full-scale if their description is entirely empirical [27,28].”

What the sources say

• ?Not checked — no full text of the sourcecites [27] Petitpas, 2018, Simulation of boil-off losses during transfer at a LH2 based hydrogen refueling station, Int. J. Hydrogen Energy source
• ?Not checked — no full text of the sourcecites [28] Zuo, 2019, Thermal stratification suppression in reduced or zero boil-off hydrogen tank by self-spinning spray bar, Int. J. Hydrogen Energy source

In the paper

“It was also shown that appreciable temperature gradients (thermal stratification) may exist within the fluid contained by the vessel.”

What the sources say

• ?Not checked — no full text of the sourcecites [7] Petitpas, G. (2018). Boil-Off Losses along the LH2 Pathway, Lawrence Livermore National Laboratory. source

In the paper

“The tank is insulated with two blankets of MLI, each having seventeen Mylar layers; however, the thickness of the insulation layer was not stated by Hasan et al. [53].”

What the sources say

• ?Not checked — no full text of the sourcecites [53] Hasan, M.M., Lin, C.S., van Dresar, N.T., and Park, F. (1991, January 1). Self-pressurization of a flightweight liquid hydrogen storage tank subjected to low heat flux. Proceedings of the ASME/AIChE National Heat Transfer Conference, Minneapolis, MN, USA.

In the paper

“A high-fidelity, physically-based BOG model would allow developers to iterate through full-scale vessel layouts completely within the design space, enabling cost and time savings by better informing decisions on the overall development path and strategy [7].”

What the sources say

• ?Not checked — no full text of the sourcecites [7] Petitpas, G. (2018). Boil-Off Losses along the LH2 Pathway, Lawrence Livermore National Laboratory. source

In the paper

“The impact of boil-off limitations on future long-term Mars missions is described in detail by Schaffer [37], who found that the payload weight of the cryogenic propulsion stages is considerably influenced by the boil-off rate.”

What the sources say

• Not checked yetcites [37] Schaffer, M. (2012). A Study of Cryogenic Propulsive Stages for Human Exploration beyond Low Earth Orbit, International Astronautical Federation.

In the paper

“Some deviation exists with the data's curvature in Test 2 (2 W/m 2 ); however, this potentially reflects that the heat flux at the beginning of the experiment was initially slightly larger than the average value.”

In the paper

“More recently, a non-equilibrium model was proposed by Wang et al. [46] to simulate LNG during storage and refuelling.”

What the sources say

• ?Not checked — no full text of the sourcecites [46] Wang, 2020, Non-equilibrium thermodynamic model for liquefied natural gas storage tanks, Energy source

In the paper

“Petitpas also presented a model to estimate the boil-off losses based on their experimental data.”

What the sources say

• ?Not checked — no full text of the sourcecites [27] Petitpas, 2018, Simulation of boil-off losses during transfer at a LH2 based hydrogen refueling station, Int. J. Hydrogen Energy source

In the paper

“However, these models were developed for LNG mixtures in specific scenarios and limited experimental or industrial data were available to verify simulations conducted using these models [56,57].”

What the sources say

• Not checked yetcites [56] Kountz, K.J. (1999). Weathering of On-Board Storage Tanks. Project Final Report, Institute of Gas Technology. IGT Project 32034-02.
• Not checked yetcites [57] Harper, G., and Powars, C. (2021, December 16). Advanced Liquid Natural Gas Onboard Storage System, Available online: https://www.osti.gov/biblio/835120-advanced-liquid-natural-gas-onboard-storage-system.

In the paper

“Several proposals based on exploiting the endothermic para-ortho conversion for cooling purposes and/or to reduce boil-off [67][68][69][70] have been considered; these efforts would be facilitated by a BOG model able to account for a vapor that is not at compositional or thermal equilibrium with the liquid.”

What the sources say

• ?Not checked — no full text of the sourcecites [67] Petitpas, 2014, Para-H2 to ortho-H2 conversion in a full-scale automotive cryogenic pressurized hydrogen storage up to 345 bar, Int. J. Hydrogen Energy source
• ?Not checked — no full text of the sourcecites [68] Ubaid, 2014, Effect of para–ortho conversion on hydrogen storage system performance, Int. J. Hydrogen Energy source
• ?Not checked — no full text of the sourcecites [69] Peng, 2013, Enhanced dormancy due to para-to-ortho hydrogen conversion in insulated cryogenic pressure vessels for automotive applications, Int. J. Hydrogen Energy source

In the paper

“This model ignores the insulation in the energy balance, instead assuming a constant rate of heat ingress into the tank; 50 W was found to yield the closest estimate to the experimental data.”

What the sources say

• ?Not checked — no full text of the sourcecites [27] Petitpas, 2018, Simulation of boil-off losses during transfer at a LH2 based hydrogen refueling station, Int. J. Hydrogen Energy source

In the paper

“Here, the industrial and experimental data of LH 2 boil-off and tank self-pressurization are compared with corresponding estimations made using BoilFAST to validate its use for liquid hydrogen storage applications.”

In the paper

“Throughout the experiment, the system remained 'static', meaning no mass transfer across the system boundary (such as refuelling) occurred.”

What the sources say

• ?Not checked — no full text of the sourcecites [27] Petitpas, 2018, Simulation of boil-off losses during transfer at a LH2 based hydrogen refueling station, Int. J. Hydrogen Energy source

In the paper

“Additionally, as this stratified mass is unusable as fuel, it becomes a liability to the payload capacity of the rocket [36].”

What the sources say

• ?Not checked — no full text of the sourcecites [36] Joseph, 2016, Effect of Insulation Thickness on Pressure Evolution and Thermal Stratification in a Cryogenic Tank, Appl. Therm. Eng. source

In the paper

“To reduce the impact of boil-off, designs incorporating multi-layer insulation, minimal tank thermal connection points, and deployable sun shields have been proposed [37].”

What the sources say

• Not checked yetcites [37] Schaffer, M. (2012). A Study of Cryogenic Propulsive Stages for Human Exploration beyond Low Earth Orbit, International Astronautical Federation.

In the paper

“Many computational fluid dynamics (CFD) and thermodynamic boil-off models have been developed for cryogenic liquids such as liquefied natural gas (LNG), including models based on heat ingress and subsequent BOG rates and those accounting for heat transfer between the vapor and liquid phases [38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55].”

What the sources say

• ?Not checked — no full text of the sourcecites [38] Miana, 2016, Comparison of evaporation rate and heat flow models for prediction of Liquefied Natural Gas (LNG) ageing during ship transportation, Fuel source
• ?Not checked — no full text of the sourcecites [39] Huerta, 2019, A realistic vapour phase heat transfer model for the weathering of LNG stored in large tanks, Energy source
• ?Not checked — no full text of the sourcecites [40] Miana, 2010, Calculation models for prediction of Liquefied Natural Gas (LNG) ageing during ship transportation, Appl. Energy source

In the paper

“In our related work [58,59], we tested and validated the SHV model against our experimental data for pure liquid nitrogen [58] and LNG-like binary mixtures of methane and ethane [59].”

What the sources say

• ?Not checked — no full text of the sourcecites [58] Perez, 2021, Measurements of boil-off gas and stratification in cryogenic liquid nitrogen with implications for the storage and transport of liquefied natural gas, Energy source
• ?Not checked — no full text of the sourcecites [59] Perez, 2021, Advanced Boil-Off Gas Studies for Liquefied Natural Gas, Appl. Therm. Eng. source

In the paper

“Furthermore, these models tend to use cubic equations of state for thermodynamic calculations, which are not optimised for the most accurate description of LNG, let alone liquid hydrogen.”

In the paper

“However, to correctly use this model for the description of liquid hydrogen storage and boil-off, it must adequately capture the influence of conversions between the two spin isomers, orthohydrogen.and parahydrogen.”

In the paper

“We have previously [58,59] presented a boil-off model based on a superheated vapor assumption similar to the non-equilibrium methods presented in the literature.”

What the sources say

• ?Not checked — no full text of the sourcecites [58] Perez, 2021, Measurements of boil-off gas and stratification in cryogenic liquid nitrogen with implications for the storage and transport of liquefied natural gas, Energy source
• ?Not checked — no full text of the sourcecites [59] Perez, 2021, Advanced Boil-Off Gas Studies for Liquefied Natural Gas, Appl. Therm. Eng. source

In the paper

“Currently, the space industry is an important user of LH 2 , with long duration storage of cryogenic hydrogen being essential in orbital transfer vehicles, the upper stages of rockets, and deep space exploration probes [29][30][31][32][33][34].”

What the sources say

• ?Not checked — no full text of the sourcecites [29] Haberbusch, 2004, Thermally optimized zero boil-off densified cryogen storage system for space, Cryogenics source
• ?Not checked — no full text of the sourcecites [30] Majumdar, 2008, Numerical modeling of propellant boil-off in a cryogenic storage tank, AIP Conf. Proc. source
• ?Not checked — no full text of the sourcecites [31] Bailey, T.E., and Fearn, R.F. (1964). Analytical and Experimental Determination of Liquid-Hydrogen Temperature Stratification, Springer. source