3O3-
3O3- t1_iycl90b wrote
Reply to comment by UnCommonSense99 in Rolls-Royce successfully tests hydrogen-powered jet engine by je97
Very cold take, H2 as approximate 3x the energy density of kerosene (120 vs 40 MJ/kg)
The problem is the size required to store it, not the mass, which is a completely separate technological issue (compression)
3O3- t1_iyezs2w wrote
Reply to comment by QVCatullus in Rolls-Royce successfully tests hydrogen-powered jet engine by je97
It does not at all, since the mass, not space (implied by the original post), is the limiting factor for flight. Imagine a standard commercial plane but 1/2 the seating space is now a fuel tank. There, you already have the 4x space, with no innovation in design, and with 1/3 of the fuel mass. As the original post pointed out however, what is currently limiting the application of H2, is in the mass (and general impracticality) of the current fuel compression technology.
There is definitely room for improvement in storage technology, and there are certainly no “fundamental constraints of physics and engineering” that limit to the mass of containers which store hydrogen to precisely what is currently available.
Simply, planes can be made much bigger (to accommodate the space needed to store the hydrogen even in the absence of significant advances in fuel compression technology) without being unviable (demonstrated categorically by the presence of huge commercial jets), which is already partly offset due to the huge mass savings thanks to very high MJ/kg of hydrogen.
If only The original commenter were working for Rolls Royce, they could have warned them it was useless due to the fundamental laws of physics and engineering, theyd have saved millions, and we would all have been spared this “greenwashing”