Cryogenic propellant tank

Much research has flourished on thomoplastics test campaigns to investigate mechanical properties, feasibility studies for components of expendable launchers and cryogenic propellant tanks, prototype production of aircraft structural parts. An even greater number of applications in aircraft interiors, cabin furnishings and missile components is known. However, these activities have not won them the rank they deserve. 

This chapter presented experimental data that characterizes a LAD channel in a dynamic outflow environment during propellant transfer from a cryogenic propellant tank over a wide range of liquid temperatures, pressures, and outflow rates. Results of the FTS LOX and LH2 pipe flow for a 325 x 2300 and 450 x 2750 screen sample shows that the screen properties show a negligible temperature dependence, and that only a small fraction of LH2 data lies outside the room temperature prediction curve. Additionally, the 450 X 2750 mesh is shown to have lower flow losses than the 325 x 2300 screen, consistent with theory. 

In addition, the simplified ID steady state pressure drop model for screen channel liquid acquisition devices has been developed and compared to the FTS, horizontal LAD, and full-scale LAD outflow experimental data. Both experimental data and model confirm that, in 1-g outflow from a cryogenic propellant tank, the hydrostatic pressure drop is the leading order term, followed by the FTS pressure drop, and frictional and dynamic losses down the channel. The model qualitatively tracks the LH2 1-g inverted outflow test results the model predicts the breakdown point within 9% for the TVS cooled channel and 18% for the standard channel. Discrepancies between 1-g model and data are primarily attributed to a non-uniform FTS pressure distribution along the channel. Results show that both LAD channels behaved close to anticipated performance and that this simplified ID model can be used to qualitatively track LAD performance in a dynamic outflow environment. 

The performance of the two PMDs, screen channels and vanes, is analyzed by comparing ability and efficiency in draining a small-scale cryogenic propellant tank in microgravity. The LH2 propellant tank is defined as a cylindrical tank with a volume of 4.05 m, a length of 2.29 m (90 in.), and a radius of0.762 m (30 in.). Compare these dimensions to the dimensions of the full-scale depot tank defined in Table 13.1. An illustration of the screen channel and vane type PMDs mounted inside the cylindrical tank is shown in Figure 14.1. 

An analydcal solution for flow through a porous channel with a single porous wall was derived and used to predict the velocity and pressure fields inside a screen channel LAD mounted inside a cryogenic propellant tank in a microgravity environment. This model... 

In the investigation reported herein, the mechanical properties of type 301 stainless steel were studied at 70, -320 and -423 F in samples of steel that had been cold-worked 42, 62, and 78. Toughness was studied by means of notched tensile tests at the same temperatures, and a notch-to-unnotch tensile ratio was calculated. The latter was taken as a criterion of resistance to brittle fracture. In addition, the tensile properties of heliarc butt-welded joints of the same materials were determined. The welded joint data were included because low-temperature properties of welded joints are of practical importance in pressurized cryogenic propellant tanks. 

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