“How can we make planes that do not rely on fuel?”
As it stands, the vast majority of the world’s air travel infrastructure rests upon hydrocarbon-based fuel. However, is there a more sustainable model to this approach? Well, if we use our engineering mindset, then we would be able to see that this jet fuel is fundamentally just energy storage, and that another option is batteries. Therefore, we can create battery-powered planes in place of their traditional alternatives. One caveat is that current battery technologies have 1/60th the energy density of plane fuels, making them a much less viable option.
“How can we make a jet that has an engine without a compressor?”
Jets are some of the most powerful machines that humans have made. However, their engines often have many fancy parts such as compressors which could result in numerous complications. So how can we completely redesign the jet engine? Well, let’s use our engineering mindset to think of this. We know that when an object goes really fast, then the air around it will also move very fast because of Newton’s third law. And if we are able to guide this air into a constricted area, then its pressure would rise immensely. And this pressure can then be used to produce thrust. So what if we were to have an aircraft move through at ultra-high velocities, capture in the surrounding air into its engines, compress it into a small area, and then heat it up to produce thrust? Well, this is the fundamental idea behind ramjets. Ramjets are able to travel much more efficiently at high velocities when compared to their traditional counterparts but require prior movement in order to operate.