Below are the first four published papers in a series of papers, whose collective objective is to analyze the scientific foundations and feasibility of the supersonic tube vehicle. Topics covered by the planned series, with main title "Hydrogen Tube Vehicle for Supersonic Transport," include (a) the concept and preliminary feasibility, (b) comparison of speed and energy with other transport modes, (c) aerodynamics in hydrogen, (d) levitation, (e) hazard analysis, including flammability and intratube noise, and (f) total cost--the sum of infrastructure, operating, maintenance.
"Hydrogen tube vehicle for supersonic transport: 4. Hydrogen propeller"
This paper, fourth in a series on the scientific foundations of the supersonic tube vehicle, discusses the hydrogen propeller. A hydrogen propeller is the method of propulsion of a conceptual supersonic vehicle that operates within a hydrogen-filled tube at cruise speed of 1 km/s. Because Mach number governs formation of shock waves at the blade tips, the high sonic speed of hydrogen allows a rotational frequency 3.85 times faster than the same propeller operating in air immediately outside the tube. RankineeFroude propulsive efficiency and e for a given vehicle Mach numberepropeller pitch and helix angle are invariant with respect to the atmosphere. To achieve constant efficiency at a given thrust and for adequate acceleration, the low density of hydrogen requires some combination of higher frequency, more blades, or larger diameter. The hydrogen propeller conceptual design employs 14 contra-rotating blades, 4.11 m diameter, and rotational frequency of 40.4 s1 at translational velocity of 970 m/s.
A. R. Miller, "Hydrogen tube vehicle for supersonic transport: 4. Hydrogen propeller." International Journal of Hydrogen Energy 2012;37(19):14603-611.Contact us for a copy of the PDF >
"Hydrogen tube vehicle for supersonic transport: 3. Atmospheric merit"
This paper, third in a series on the scientific foundations of the supersonic tube vehicle, compares 24 common gases as potential operating atmospheres for tube vehicles,and equations are derived for aerodynamic (tunneling) performance of the atmosphere and molar energy density of the tube vehicle. Aerodynamic performance is a function of the speed of sound and Reynolds number, and energy density is a function of the free energy of reduction or oxidation of the tube gas and the stoichiometric coefficients of the stored reactants. The product of these two parameters determines the rank of atmospheric merit. Hydrogen exhibits the highest aerodynamic performance...
A. R. Miller, "Hydrogen tube vehicle for supersonic transport: 3. Atmospheric Merit." International Journal of Hydrogen Energy 2012;37(19):14598-602.Contact us for a copy of the PDF >
"Hydrogen tube vehicle for supersonic transport: 2. Speed and energy"
This paper, second in a series on the scientific foundations of the supersonic tube vehicle, tests the hypothesis that the STV will be simultaneously fast and energy efficient by comparing its predicted speed and energy consumption with that of four long-haul passenger transport modes: road, rail, maglev, and air. Consistent with the hypothesis, the concept vehicle is both the fastest and lowest energy consuming mode. In theory, the vehicle can cruise at Mach 2.8 while consuming less than half the energy per passenger of a Boeing 747 at a cruise speed of Mach 0.81.
A. R. Miller, "Hydrogen tube vehicle for supersonic transport: 2. Speed and energy." International Journal of Hydrogen Energy, 35:11 (2010) 5745-5753.Download the PDF >
"Hydrogen tube vehicle for supersonic transport: Analysis of the concept"
The first in the supersonic tube vehicle paper series, this paper analyzes the feasibility of the concept of a hydrogen tube vehicle for supersonic transport. It proposes a conceptual design--power source, propulsion, levitation, and guidance--and then analyzes its feasibility--power and energy requirements, vehicle packaging, levitation by gas bearings, and safety.