Design method of scramjet fuel injection system

Abstract

The invention discloses a design method of a fuel injection system for a scramjet engine and relates to a near space vehicle. Nozzles can be distributed in the following three ways: according to flowing characteristics, the nozzles are distributed on a near vortex wall surface circumferentially, or distributed along the flowing direction, or distributed in a 'triangle' shape on the near vortex wall surface. In the component design of the existing scramjet engine, the defect that the outlet uniformity needs to be controlled as much as possible in the design of a gas inlet channel, while a non-uniform vortex structure needs to be artificially introduced in the design of a combustion chamber, is solved. By virtue of a low-energy / low-velocity zone and a corner vortex structure of the outlet of a three-dimensional internal-retraction gas inlet channel, the nozzles of a combustion chamber are reasonably arranged, the relation of flowing characteristics between the gas inlet channel and a supersonic combustion chamber is strengthened, and the fuel injection and mixing effects can be enhanced, so that the combustion efficiency is raised indirectly, and the overall performance of the scramjet engine is improved.

Description

Technical field [0001] The invention relates to a near-space aircraft, in particular to a design method of a scramjet fuel injection system considering the flow characteristics of an intake port. Background technique [0002] Near-space vehicle research is currently one of the focuses of international competition for space technology, and scramjet research has become the top priority of the development of near-space vehicles due to its important strategic significance. The world powers represented by the United States, Russia, Germany, France, and Australia are all vigorously promoting their own scramjet development plans. Among them, fuel injection, blending and ignition are one of the key difficulties in achieving supersonic combustion and even hypersonic flight. Since the main flow velocity in scramjet is mostly supersonic, the flow captured by the intake port usually only has a residence time of milliseconds in the engine runner. It is very difficult to complete the deceler...

AI Technical Summary

Problems solved by technology

There are three reasons for this: (1) In order to effectively simplify the design goals and flow conditions; (2) There is no effective information transmission and feedback mechanism between the two independently designed sub-components; (3) The flow field at the outlet of the inlet and the internal flow field of the combustion chamber lack sufficient understanding, for example: how to understand the influence of complex flow phenomena such as turbulent vortex characteristics on unsteady characteristics such as fuel injection and mixing in the combustion chamber

[0006] At the same time, an obvious problem is that it is very difficult to obtain a completely uniform outlet flow for a hypersonic inlet

If only considering the uniformity of the inlet outlet, the inlet designer can only take additional measures (such as active control of the flow field) to suppress this outlet non-uniformity, which will undoubtedly bring additional flow loss

Images