The Conceptual Design And Research On Multi-bypass Counter-rotating Air-water Engine

Aero-engine that has reputation as "flower of industry" is a kind of extremely complex and sophisticated thermal machinery, which has a decisive influence on the performance, reliability and affordability of aircrafts. With the progress of technology,aircrafts demand higher and higher requests for aero-engine. Air-water amphibious aircraft which has the capability of fighting amphibiously make a new developmental request for air-water amphibious engine naturally. The air-water amphibious power plant has become the focus of the research of combat equipment across the world with the development of relative techniques and the impulse of application requirements.This article creatively puts forward the new concept design of multi-bypass counter-rotation air-water amphibious engine based on the reasonable integration of traditional engine and new techniques of engine, in order to meet the demand of the new era makes to aero-engine. In the new conceptual design, the central shaft of the engine is removed, and realizes the counter-rotation of the compressor and turbine with the structure of inner and outer shell, achieving the purpose of the reduction of the weight and the axial dimension of the engine, improving the thrust-weight ratio and structural efficiency at the same time. Integrate the metal/water reaction ramjet on the basis of the construction of central bypass, making the amphibious work of the new concept engine come true. A relatively complete and feasible conceptual scheme is proposed via the analysis of the operational principle of the new engine and the conceptual design of overall scheme and related components. The overall 3D model of the new engine is established.The essential part of the new engine for working amphibiously is metal/water reaction ramjet. A preliminary analysis and calculation for the performance of metal/water ramjet is conducted, taking thrust F and specific impulse I as the influence factor. The theoretical calculation and analysis indicate that satisfied promotion performance is obtained. Establish a 3D model for metal/water reaction ramjet with CATIA, and choose mutually independent parameters——the distance between metal fuel entrance and water entrance, the radius of nozzle as the objects of study to conduct flow field simulation. The diagrams of flow field parameters of combustion chamber varying with the change of the structural parameters are obtained.The structural model of metal/water reaction ramjet is determined via the comparison of simulation which could provide the theoretical basis for the further design andoptimization of metal/water reaction ramjet.The simulations of models of hanging blades of outer shell and traditional compressor rotor are conducted with finite element method. The results indicate that the maximum von mises stresses of hanging blades of outer shell have not exceed the yield limit of material, and it is able to meet the strength requirement of compressor rotor blades for operating properly in the sky after the comparison and analysis of the simulation outcome of different rotational speed. Compare and analyze the hanging blades to traditional compressor blades, we finding out that the von mises stress of hanging blades is less than traditional blades, and the stress distribution of hanging blades is superior to the traditional ones. The conclude shows that the deformation of hanging blades is significantly less than traditional ones. So it is obvious that the material requirement of hanging blades is lower than traditional ones, and the hanging blades do a greater job in reliability and affordability.