Liu Zhirang, deputy of the National People's Congress and director of the Sixth Institute of China Aerospace Science and Technology Corporation, told the Science and Technology Daily reporter that China is continuing to carry out research on rocket power reusable technology represented by liquid oxygen hydrocarbon engines, breaking through the continuous heat of products. A number of key technologies such as commissioning, wide-range thrust adjustment, multiple starts, and rapid use of re-use.

The biggest dream of space transportation is to develop reusable carriers to achieve "fast, cheap, reliable" access. Internationally, companies such as SpaceX and Blue Origin have taken the lead in the success of partial recovery and reuse of rockets.

Liu Zhirang introduced that China has also formulated a development plan for the reuse of vehicles, and proposed three technical approaches in accordance with the goals of near, medium and long-term, and simultaneously carried out work and ladder formation capabilities. Based on the active rocket configuration, the main engine re-use technology research and adaptability improvement work, the recovery verification work is completed in the near future, and the safety problem of the falling area is solved. Based on the new research rocket configuration, research on re-use of liquid oxygen hydrocarbon engine is carried out to support vertical , level and other recycling programs, medium-term rocket re-use capability in the medium term, promote the formation of two-level orbital space transportation industry; re-use the vehicle configuration based on horizontal take-off and landing, carry out research on aspirating combined engine, long-term formation Engineering applications for single stage orbital carriers. He said that the Sixth Hospital has focused on the re-use of aerospace liquid power and promoted research work as a whole in accordance with the planned three technical paths. However, the engine is the most demanding in all heat engines, posing great challenges for reuse.

Compared with disposable rockets, reusable rockets must first be able to return and recover. This process puts high demands on the rocket engine's thrust regulation capability. Liu Zhirang said that the current rocket engine has a certain ability to change, and the thrust can be reduced to about 70% of the rated thrust. However, to meet the recycling requirements, the thrust needs to be reduced to 40% or even 30% of the rated. The larger the range of the push, the more difficult the design.

Taking the engine combustion device as an example, in general, it is necessary to adjust the fuel flow rate in order to adapt to the thrust change, that is, in the case where the injection flow rate is greatly changed, the parameters such as the pressure of the mixed combustion are maintained within an appropriate range, so as to ensure relative sufficient. combustion. This requires that the nozzle flow path of the combustion device must be able to follow the adjustment. Otherwise, it is not only impossible to guarantee the quality of the spray mixing combustion under the corresponding thrust flow, and even the medium and low frequency vibration or the high frequency combustion instability may occur, resulting in structural damage of the product.

The one-off rocket engine may have completed its mission in a matter of minutes, and the working life of the reusable engine needs to be greatly increased. This requires the engine design concept to shift from strength design to life design and to address technologies such as structural reliability, health management, use and maintenance and rapid inspection, life prediction and evaluation.

Liu Zhirang said that in order to meet the requirements of repeated use, the engine structure needs to be assessed. After the engine is operated once, the engine state is quickly evaluated, including structural integrity and sealing reliability. In addition, there are many substances left in the tunnel, whether it needs cleaning, cleaning to what extent, whether there is chemical reaction or corrosion problems, etc., all need to be studied in depth. “From long-life design to ensuring structural reliability and quality stability, this is a problem,” he said.

In addition, Liu Zhirang revealed that the Sixth Institute aimed at a farther future and carried out research on combined cycle power technology and ground integration tests. The technology is intended to combine aero-engines, ramjets and rocket engines to develop strengths in different environments, both inside and outside the atmosphere. He said that all three forms of power are constantly evolving. If they can be combined, they will be a great innovation. However, in order to maximize the overall structural benefits, optimize flight orbit and good economic benefits, they also face multiple difficulties.

It is understood that if the combined cycle power is successfully developed, it can support the service of the horizontal take-off and landing to re-use the aircraft, which will greatly improve the ability to quickly enter and exit the space.

Pearl Cotton Bag Cutting Machine

Pearl Cotton Bag Cutting Machine,Front Sealing Bag Cutting Machine,High-Speed Bag Cutting Machine,Square Bottom Bag Cutting Machine

Dongguan Yuantong Technology Co., Ltd. , https://www.ytbagmachine.com