Design method of improved scram combustion chamber and its swirler

Abstract

The invention discloses a modified scramjet combustion chamber and a design method of a swirler thereof. The swirler capable of causing air flow to generate helical motion is arranged in a combustion chamber and comprises a rotational flow generation upper wallboard, a rotational flow generation lower wallboard, a back end surface wallboard and a sidewall mounting surface, wherein the rotational flow generation upper wallboard is used for making the air flow entering the combustion chamber generate oblique shock waves, and the rotational flow generation lower wallboard is used for making the air flow entering the combustion chamber generate expansion waves. The sidewall mounting surface is connected with the combustion chamber, and the front edge of the swirler faces to an inlet of the combustion chamber; the back end surface wallboard is arranged opposite to an outlet of the combustion chamber; the interior of the swirler is provided with a fuel conveying embedded pipe; an inlet of the fuel conveying embedded pipe is arranged on the sidewall mounting surface; and an injection opening of the fuel conveying embedded pipe is arranged at the back end surface wallboard. Therefore, the invention has the advantages of improving the mixing efficiency and the combustion efficiency of the fuel of a scramjet, shortening the lengths of an engine isolating section and the combustion chamber, further optimizing the structure of the engine, increasing the thrust-weight ratio of the engine and improving the whole performances of the engine.

Description

technical field [0001] The invention relates to a scramjet combustion chamber, which is mainly used in a scramjet engine. Background technique [0002] At present, common scramjet inner runners, such as figure 1 As shown, it mainly includes an intake port 1', an isolation section 2', a combustion chamber' and a nozzle 4' connected in sequence. [0003] Supercombustion chambers are mainly used to achieve uniform mixing and full combustion of oil and gas in supersonic airflows. They have huge development potential and are increasingly valued and concerned by various countries. However, in the existing supersonic combustion chamber, it is difficult to mix oil and gas and the flame is difficult to stabilize, and the total pressure recovery coefficient and combustion efficiency of the combustion chamber are low, which leads to unsatisfactory working performance of the supersonic combustion chamber. In addition, when the airflow burns in the super-combustion chamber, it will gen...

AI Technical Summary

Problems solved by technology

However, in the existing supersonic combustion chamber, it is difficult to mix oil and gas and the flame is difficult to stabilize, and the total pressure recovery coefficient and combustion efficiency of the combustion chamber are low, resulting in unsatisfactory working performance of the supersonic combustion chamber

In addition, when the airflow burns in the super-combustion chamber, it will generate a higher pulsating pressure, and this pulsating pressure will continue to propagate upstream through the boundary layer of the combustion chamber wall and the separated subsonic airflow, so in order to avoid the pressure pulsation in the combustion chamber The impact on the upstream intake port requires the design of a longer isolation section, resulting in an increase in the mass load of the engine, and also reduces the thrust-to-weight ratio of the scramjet engine, while supersonic airflow is generated in the longer isolation section The friction loss is very large, so that the total pressure loss when entering the combustion chamber inlet is relatively large

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