I can imagine the following engine options for New Concorde:
a) 4 turbofan jet engines of the outer size of the jet engines of the first Concorde, they were possible to be produced with "micro-turbines" in the first jet stream (an idea of Jaguar motor cars, that weighs 30 kgs)...
b) 2 turbofan jet engines with a traditionally sized first stream and with 2 side fans/ inner rotors each - so that the turbofan jet engines with the traditionally sized first stream remain flat...
Breaking through the sound barrier could be possible by 2 methods:
c) Using afterburners or reheat of modern design where the jet fuel didn't flow or swamp into the afterburner but the jet fuel was lead by high-pressure compressors and by high-pressure pipes to the combustion chamber and the jet fuel was only vapourized into the combustion chamber - reaching a far better fuel-efficiency and much cleaner exhaust gases than in the Concorde of the 1970s (this idea of mine for the enhancement of the reheat of supersonic jets is based on the common-rail diesel technology of Mercedes-Benz)...
d) After the "advance technology winglet" of the Boeing 737 MAX in case of New Concorde "skirt-winglets" could be used that meant nearly the entire upper surface of the delta-wings was folded out and forward (around a turning joint in the very beginning of the delta-wings) so that the wing surface of New Concorde was nearly doubled at higher altitudes and at higher speeds... Thus New Concorde became a flying wing airplane and could reach supersonic speeds perhaps without reheat, too... I would say yes, the delta-wings of New Concorde can be produced out of modern composite materials, too...
I do hope that applying the above technologies noise level, fuel-efficiency and cleanness of the exhaust gases of New Concorde were able to meet 21st Century expectations...
Best wishes, Joseph de la Mikula and Team
