MH4UAstragon

Fischer-Tropsch synthetic fuels seem to be the most viable option at the moment. They work with any feedstock material so the process can use cleaner fossil fuels (like natural gas at the moment) and then switch to fast-growing biomass (algae, kudzu, duckweed, etc). Or the Methanol-to-Gasoline Process specifically to make Gasoline. Excess Methanol would be the Octane Booster instead of Ethanol we use now. Biodiesel made from algae oils will still be relevant even with FT processes because engines run so much better on the stuff. Lubricates and cleans out engine better than normal diesel and doesn't produce the infamous "diesel stink" from sulfur.

In this design, the engine is a combination of diesel and jet engine technology. A 36-cylinder diesel engine is the core part of the concept, operating like a pair of linked up 18-cylinder motors. The front engine is a bit wider than the rear one, but has a wider, hollow crankshaft rotating one way while the rear engine crankshaft rotates the other way and extends through the first one. Questions regarding the piston portion of the engine: - In this idea, the engine uses lightweight but strong high temperature alloys. I'm imagining it to be a mix of beryllium, titanium, and magnesium, maybe the cylinders could be made from high-temperature strength steel if need be. I do know that beryllium greatly reduces fire hazards from other metals it is alloyed with, so is this combination viable? - The engine is a "star" configuration, or liquid-cooled radial. The aircraft it is mounted on would be able to go well past mach 2. Air passes around a shock cone akin to what the SR71 used in its engines, one or more Stirling Coolers powered by the engine itself cool down the intake air, some of the air gets combusted while the rest flows around the engine inside its cowling, passing over a ring of radiators. The two halves of the engine drive a pair of conta-rotating ducted fans. One half of the engine also drives a centrifugal supercharger, while the other drives the Stirling coolers. The whole engine is turbo-compound, driving an Axial Compressor in front of the supercharger. The main question here is about the Stirling Coolers: can they remove the heat from the air before it reaches the engine and release it behind it fast enough to keep up with this? - As an alternative idea to cool the motor, is regenerative cooling (like how rocket engines keep their nozzles cool) actually feasible in a piston-type engine, where fuel would flow around the cylinders, remove a good deal of heat, and then the hot fuel would combust in the cylinders (for a possible efficiency gain in combustion?)? Once air has flown through this part of the engine, it then can be compressed by another, larger Axial Compressor, mixed with fuel, and combusted for jet thrust. If the reader is having trouble wrapping their mind around this, picture it as a turbofan engine fused with the motorjet concept. The motor powers the fan part of the engine and the jet combustion can be turned on or off as needed. Due to alloy choice, the motor part of the engine would produce at least 6000 or more HP while weighing roughly half that. The total weight of the engine would not be all that much higher than modern jet engines. The aircraft this engine would go in is part of an idea for a video game I have, but I want the idea to be scientifically possible and not leap headfirst into scifi stuff unless there is no other alternative.