While it is true that the advancement of technology has reached its peak today, technology today has not been able to surpass some of the creations made in the past. This may be due to the fact that it is not necessary to spend time on such designs. However, it is surprising that the world's fastest aircraft was built in 1966 and that record lasted until the end of two decades in the 21st century. This article is about this great design known as Lockheed SR - 71 or Black Bird.
A challenge from the Soviet Union to the United States
After World War II, the Cold War between the United States and the Soviet Union reached its peak in the mid-1950s. The main reason for this is the lack of access to information on US war secrets in the Soviet Union. It was essential for the United States to obtain accurate information on the deployment of weapons in the Soviet Union, especially near the Soviet border.
The Soviet network of radar stations, SAM (Surface to Air Missile) missile launchers, and interceptor aircraft headquarters helped to keep the United States out of its territory. The U.S. Air Force 'U-2 reconnaissance aircraft entered the Soviet Union in 1956, but it was not fast or stealth. Because it was capable of flying at 70,000 feet, the United States believed that Soviet anti-aircraft weapons such as the S-75 Dvina would not reach the maximum limit of 60,000 feet.
S-75 Dvina missile and U-2 aircraft
The United States now recognized the need for a high - speed stealth aircraft capable of spying on the Soviet Union. Its construction was accelerated on May 1, 1960, when the Soviet Union shot down a U-2 spacecraft flying at 68,000 feet. Here the pilot flew off the plane with the help of a parachute, but was captured by Soviet troops. Management United StatesIt was said that the plane was sent for meteorological observation, but after the Soviet Union released photographs of the plane, the United States had to accept its true purpose.
During 1957-58, at the request of the US government, the Lockheed and Convair aircraft manufacturers submitted several project proposals for reconnaissance aircraft. Lockheed's design was for the A-11 and A-12 Oxcart aircraft, which were introduced by Convair as Kingfish and Fish. The US government has selected Lockheed's A-12 aircraft as its future spy aircraft. The aircraft was further developed and later manufactured as the SR-71.
The shape presented for Convair's Kingfish aircraft
Ramjet technology
It was not until 1942 that it was discovered that jet engine power had to be used instead of conventional engine power to accelerate an aircraft. This jet engine is called the Turbojet engine. In this case, a powerful jet stream is created by burning the compressed air with fuel at a high temperature using a mechanically rotating air compressor. This stream of air rotates the air compressor to obtain further airflow, which in turn pushes the aircraft forward.
The overall efficiency of the turbojet engine is low, as it consumes part of the air current generated by the turbojet engine. As a result, an aircraft cannot accelerate more than 2 times the Mach number (Mach number - times the speed of an object). The Ramjet engine is a type of jet engine that has been identified and developed. The main difference between this engine and the Turbojet engine is the air compression.To do this, use a scooped Ram instead of a mechanical compressor. It can go up to 6 Mac numbers
Turbojet engine and mechanical parts Minimal Ramjet engine
The disadvantage of this technique is that its jet current is not generated at rest. Therefore, the aircraft with the Ramjet must be lifted up and released with the help of another aircraft. In order not to get the help of another aircraft, you have to go for a hybrid system that combines the above two Turbojet and Ramjet methods. That is how Pratt & Whitney, an American aircraft manufacturer, developed the J-58 jet engine.
This is then used for Lockheed A-12 and later for SR-71.
J-58 engine that took jet engine technology to the limit
The J-58 can be described as an engine that took jet engine technology to the maximum. The main casing of the J58 engine includes a Turbojet engine. Around it and in front of it can be seen a complex control mechanism that controls air circulation. That mechanism converts this turbojet engine into a ramjet engine during flight.
J-58 engine
The front inlet spike of the J58 engine differs from that of a typical ramjet engine in that it can move forward and backward. It can control the amount of air entering the engine as well as change the location of the shock wave in front of the tip. When an object moves faster than the speed of sound, the air particles around it create vibrational waves. These have shock wavesThis causes vibration of the moving object and creates a drag force. Changing the location of the shock waves can minimize its adverse effects.
The inlet spike section is at the maximum forward position, with the aircraft speed up to 1.6 Mac. When its speed exceeds Mac 1.6, the location where the shock wave is generated changes. Because of this, the spike section moves back and forth 41mm for every Mac number 0.1 change. Then the shock wave is maintained at the most suitable position and the energy loss is minimized.
The inlet spike section in front of the J-58 engine and the casing around the engine
In the engine casing, a bypass area is created around the turbojet engine to cool the engine with the air passing through it. Then its efficiency can be increased and it can travel faster. In addition, this air mixes with the combustion gas at the rear of the engine, expanding the rear jet stream, which then accelerates the aircraft. In addition to the engine 's main burner, there is a rear burner
(After burner) can be seen in this engine. This part adds fuel to the exhaust gas from the turbojet engine for extra thrust and expansion. All of the above processes allow the J58 dual engine to deliver up to 5 Mac (6174 km / h)A pair of J58 engines can give an aircraft about the same speed.
The black bird builds up
The J58 engine was added to the A-12 and was first launched in 1962. The plane was flying at a maximum altitude of 90,000 feet during a test flight and was flying at a speed of 3550 km per hour. Its speed is 2.87 Mac, but the manufacturers claim that this aircraft can reach a speed of 3.2 Mac.