Composite heat-insulation layer for engine

Abstract

The invention discloses a composite heat-insulation layer for an engine. The passive weight of the engine product is reduced, the effective weight is improved, a strike ability is improved, the ablation resistance and an anti-erosion performance of the heat-insulation layer are improved, and the working time and the working reliability of the engine are improved. The heat-insulation layer providedby the invention is formed by a silicone rubber heat-insulation layer and a ceramic precursor material, wherein the silicone rubber heat-insulation layer is prepared from the components in percentageby weight: 45 percent to 50 percent of addition type silicone rubber, 25 percent to 28 percent of ammonium polyphosphate, 13 percent to 15 percent of phenolic microspheres, 1.5 percent to 3 percent of mullite fiber, 1.5 percent to 3 percent of short-cut aramid fiber, and 8 percent to 10 percent of high silica fiber. The composite heat-insulation layer for the engine provided by the invention is applied to heat protection of solid-ramjet, liquid-ramjet and high-pressure-ramjet engines under severe working conditions.

Description

technical field [0001] The invention relates to a composite thermal insulation layer, which is suitable for scramjet engines with solid impulse and liquid impulse. Background technique [0002] Thermal protection of ramjet afterburning chamber is one of the key technologies of ramjet. The main function of the heat insulation layer is to resist the erosion of high-temperature gas for a long time, and to protect the engine casing from heat. Thermal protection insulation layer materials can be divided into elastic and rigid two categories. Rigid heat protection insulation layer materials have excellent ablation resistance and erosion resistance, such as carbon-carbon composite materials, composite materials based on phenolic resin, etc., but due to their low elongation, they cannot adapt to the large strain of the engine casing during operation. Now the engine heat protection insulation layer generally adopts elastic heat protection material. The development of the elastic t...

AI Technical Summary

Problems solved by technology

[0003] During the working process of the liquid ramjet engine, the airflow velocity is high and the flow rate is large, especially at the air inlet, the vortex and vortex phenomenon are serious, and the ablation and erosion of the heat insulation layer are very severe. The existing high-performance silicone rubber heat insulation layer is used in the engine. During the process, the local wall temperature rises rapidly, forcing the engine to stop before the design working time. With the development of rocket and missile technology, higher and higher requirements are put forward for the heat insulation layer. A single elastic heat protection material can no longer meet the thermal protection requirements