September 29, according to the Civil Aviation Administration, a ceremony was held at Beijing Capital Airport , and the C919 aircraft model certificate was officially issued to COMAC, and the C919 will soon begin commercial operation. Is the C919 an advanced aircraft in the world? Where is its advancedness reflected? This is a question that many netizens are concerned about, and some netizens may even think that we just assemble foreign spare parts and systems and become C919.
C919 is a large aircraft designed by my country as a whole. The aircraft is a very complex system. Unlike some people imagine, simple parts and components can be used to make the aircraft. The overall system design and integration of aircraft is very difficult and requires very high technical level and organizational management capabilities.
Aeroplane aerodynamic design (appearance) is a very high-tech job. The aircraft can fly and fly safely, stably, controllable and economically. The aerodynamic appearance of the aircraft is the most important. Therefore, the aerodynamic design of an aircraft is the most core design work of the aircraft, with high technology and great difficulty.
This is hard for ordinary people to imagine. We can think about it this way. The airplane can only be thought about in the air and has a density of only one-to-one-thousandth of water. Everything it takes to fly and control is achieved through changes in posture and aerodynamic shape. Is it a little difficult? It is actually super difficult. The following five points in
are the advantages of C919 we made ourselves.
1. Supercritical wing design. Supercritical wing is a wing with a special wing profile (aircase). Aircraft with this airfoil design can greatly improve aerodynamic performance in the transonic range, reduce drag and improve attitude controllability.
2. Add winglets, similar to the small wing surface of the wing surface, approximately perpendicular to the wing surface. During the flight, the high-pressure zone airflow in the lower wing surface of the wing surface will flow around the wing tips to the upper wing surface, which takes away energy and increases drag. wing tip winglet is used to weaken this resistance.
C919 adopts a supercritical wing design, adding winglets to indicate that Chinese aircraft design level has reached the world's leading level.
3. C919 uses a variety of new materials. 1) aluminum lithium alloy has low density, high strength and excellent damage tolerance . 2) Titanium alloy has the advantages of lightweight, high strength and good corrosion resistance, and is known as "space metal". 3) ultra-high strength steel is a high-strength, high-toughness alloy steel . 4) Composite materials have also become one of the key materials, most of which are carbon fiber /epoxy resin composite materials.
The widespread use of new materials, reducing the weight of the aircraft, increasing the strength of the aircraft, increasing the service life of the aircraft, making the aircraft safer and more controllable.
4. C919 has "big eyes" than similar passenger aircraft. It will reduce the design of 6 windshields of ordinary aircraft to 4, reducing flight resistance, enlarging the driving vision, and reducing structural weight. The four single windshield glass poses a challenge to the structural design of the aircraft's nose. The 919 aircraft adopts an integrated window frame and a load-bearing windshield, which are great innovations in design and production.
5. Because of the use of these advanced materials, technologies and designs, the C919 fuselage is wider than that of the same type of aircraft. The seats, aisles and heights in the cabin are relatively spacious, which improves riding comfort. .
comprehensively, C919 has reached the world's advanced level in all aspects such as safety, aerodynamics, noise isolation, and comfort.
In addition, the engine and avionics control of C919 all use mature and advanced foreign products, so I won’t introduce it here.
