The advantages of powder fuel ramjets compared to traditional ramjets

Powder fuel ramjet is a new type of ramjet that uses high-energy metals (Al, Mg) or boron as fuel and ram air as oxidant and working medium. Because its fuel form is small solid particles at room temperature, compared to traditional liquid fuel ramjets and solid rocket ramjets, powder fuel ramjets have the following advantages: (1) Powder fuels (Al, Mg, B) have high energy and heat Therefore, the ramjet fueled by it has a higher specific impulse and density specific impulse. (2) The fuel form of the powder fuel ramjet is solid powder at room temperature. Compared with the solid propellant in the form of conventional grains, there is no storage aging problem, so the fuel cost is greatly reduced; at the same time, the powder fuel has a higher ratio than the solid propellant. The anti-sensitivity of the powder fuel greatly improves the safety of the powder fuel in the manufacturing, storage and use process, even in the high overload environment. (3) The powder fuel flows in a gas-solid two-phase form under the action of fluidized gas, so it has a strong flow rate controllability, so that the powder fuel ramjet has multiple starts and thrust adjustment functions. At the same time, the fuel flow adjustment of the powder fuel ramjet is a cold adjustment method, and its density specific impulse is higher. Compared with the current adjustable flow ramjet engine under development, it has better performance and is especially suitable for large working airspace and requiring multi-ballistic flight. And other tasks. (4) With the increase of the missile's flying Mach number, the temperature of the air entering the combustion chamber continues to rise. The high-temperature combustion products of hydrocarbon fuel used in conventional ramjet engines are prone to dissociation, resulting in a rapid decrease in the engine specific impulse, while powder fuel is Without this problem, even in high-speed flight, the energy can still be fully released. Therefore, powder fuel is also an ideal scramjet fuel. (5) The powder fuel delivery form is flexible, and it can be used with the existing solid fuel or liquid fuel ramjet to form a solid/powder, liquid/powder combined ramjet, thereby improving the specific impulse performance of a single fuel type ramjet. It can be seen that the many advantages of the powder fuel ramjet make it have strong development potential, but because it is still in the preliminary research stage and involves many aspects such as gas-solid two-phase transportation, particulate fuel ignition and engine combustion organization, the current Many technical problems have not been resolved. This article gives a detailed overview of the development status of powder fuel ramjet and related fields, and at the same time combs its key technologies, to provide a certain reference for powder fuel ramjet researchers. Previous post: 2018 prospects for the import and export of metal stamping parts industry