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Liquid Rocket Propellant
The highest specific impulse chemical rockets use liquid propellants (liquid-propellant rockets). They can consist of a single chemical (a monopropellant) or a mix of two chemicals, called bipropellants. Bipropellants can further be divided into two categories; hypergolic propellants, which ignite when the fuel and oxidizer make contact, and non-hypergolic propellants which require an ignition source. About 170 different propellants made of liquid fuel have been tested, excluding minor changes to a specific propellant such as propellant additives, corrosion inhibitors, or stabilizers. In the U.S. alone at least 25 different propellant combinations have been flown. Many factors go into choosing a propellant for a liquid-propellant rocket engine. The primary factors include ease of operation, cost, hazards/environment and performance. History Development in early 20th century Konstantin Tsiolkovsky proposed the use of liquid propellants in 1903, in his article ''Exploration ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specific Impulse
Specific impulse (usually abbreviated ) is a measure of how efficiently a reaction mass engine, such as a rocket engine, rocket using propellant or a jet engine using fuel, generates thrust. In general, this is a ratio of the ''Impulse (physics), impulse'', i.e. change in momentum, ''per mass'' of propellant. This is equivalent to "thrust per massflow". The resulting unit is equivalent to velocity. If the engine expels mass at a constant exhaust velocity v_e then the thrust will be \mathbf = v_e \frac . If we integrate over time to get the total change in momentum, and then divide by the mass, we see that the specific impulse is equal to the exhaust velocity v_e . In practice, the specific impulse is usually lower than the actual physical exhaust velocity inefficiencies in the rocket, and thus corresponds to an "effective" exhaust velocity. That is, the specific impulse I_ in units of velocity *is defined by* : \mathbf = I_ \frac , where \mathbf is the average thrust. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War II
World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the world's countries participated, with many nations mobilising all resources in pursuit of total war. Tanks in World War II, Tanks and Air warfare of World War II, aircraft played major roles, enabling the strategic bombing of cities and delivery of the Atomic bombings of Hiroshima and Nagasaki, first and only nuclear weapons ever used in war. World War II is the List of wars by death toll, deadliest conflict in history, causing World War II casualties, the death of 70 to 85 million people, more than half of whom were civilians. Millions died in genocides, including the Holocaust, and by massacres, starvation, and disease. After the Allied victory, Allied-occupied Germany, Germany, Allied-occupied Austria, Austria, Occupation of Japan, Japan, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitric Acid
Nitric acid is an inorganic compound with the formula . It is a highly corrosive mineral acid. The compound is colorless, but samples tend to acquire a yellow cast over time due to decomposition into nitrogen oxide, oxides of nitrogen. Most commercially available nitric acid has a concentration of 68% in water. When the solution contains more than 86% , it is referred to as ''fuming nitric acid''. Depending on the amount of nitrogen dioxide present, fuming nitric acid is further characterized as red fuming nitric acid at concentrations above 86%, or white fuming nitric acid at concentrations above 95%. Nitric acid is the primary reagent used for nitration – the addition of a nitro group, typically to an organic molecule. While some resulting nitro compounds are shock- and thermally-sensitive explosives, a few are stable enough to be used in munitions and demolition, while others are still more stable and used as synthetic dyes and medicines (e.g. metronidazole). Nitric acid is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walter HWK 109-509
The Walter HWK 109-509 was a German liquid-fuel bipropellant rocket engine that powered the Messerschmitt Me 163 Komet and Bachem Ba 349 aircraft. It was produced by Hellmuth Walter Kommanditgesellschaft (HWK) commencing in 1943, with licensed production by the Heinkel firm's facilities in Jenbach, Austria. Design and development Early versions of the Me 163 had been powered by an earlier design running on a "cold engine" fueled with Z-Stoff. This fuel tended to clog the jets in the combustion chamber, causing fluctuations in power and potentially explosions. Worse, however, was the fact that the engine could not be throttled, and when the aircraft leveled off after its climb to altitude it quickly accelerated to speeds that caused serious compressibility issues. The RLM demanded that a version be developed with a throttle. During this period Walter had also been working with a new fuel known as C-Stoff that gave off significant heat and was thus known as the "hot engin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C-Stoff
C-Stoff (; "substance C") was a Redox, reductant used in bipropellant rocket fuels (as a fuel itself) developed by Hellmuth Walter Kommanditgesellschaft in Germany during World War II. It was developed for use with T-Stoff (a high-test peroxide) as an oxidizer, which together with C-Stoff as the fuel, forms a hypergolic fuel, hypergolic mixture. The proportions of the components in C-Stoff were developed to catalyse the decomposition of T-Stoff, promote combustion with the oxygen released by the decomposition, and sustain uniform combustion through sufficient quantity of the highly reactive hydrazine. The combination of the C-Stoff, used as a rocket fuel, with the T-Stoff used as the oxidizer, often resulted in spontaneous explosion from their combined nature as a hypergolic fuel combination, necessitating strict hygiene in fueling operations; there were numerous catastrophic explosions of the Messerschmitt Me 163 aircraft that employed this fuel system. Another hazard was tox ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henschel Hs 293
The Henschel Hs 293 was a World War II Nazi Germany, German Command guidance, radio-guided glide bomb. It is the first operational anti-shipping missile, first used unsuccessfully on 25 August 1943 and then with increasing success over the next year, damaging or sinking at least 25 ships. Allied efforts to jam the radio control link were increasingly successful despite German efforts to counter them. The weapon remained in use through 1944 when it was also used as an air-to-ground weapon to attack bridges to prevent the Allied breakout after D-Day, but proved almost useless in this role. Development The Hs 293 project started in 1940, based on the "Gustav Schwartz Propellerwerke" pure glide bomb designed in 1939. The Schwartz design did not have a terminal guidance system; instead, it used an autopilot to maintain a straight course. It was intended to be launched from a bomber at sufficient distance to keep the aircraft out of range of anti-aircraft artillery, anti-aircraft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walter HWK 109-507
The HWK 109-507 was a liquid-propellant rocket engine developed by Germany during World War II. It was used to propel the Hs 293 anti-ship guided missile. It was produced by Hellmuth Walter Kommanditgesellschaft (HWK). Like other Walter engines it used hydrogen peroxide as a propellant. Missile The Hs293 has been variously described as a missile or as a boosted glide bomb. It consisted of an SC500 bomb casing, fitted with wings, engine and radio control. Control equipment was housed in a rearward extension of the bomb casing but the motor was mounted in a separate housing beneath. It had originally been developed as an unpowered glide bomb, "Gustav Schwartz Propellerwerke", and the engine was added later. After flight tests, a visible tracking flare was also added, in a further rearward extension. As the engine was mounted below the missile fuselage, the exhaust nozzle pointed downwards at 30°, so as to align the line of thrust with the centre of gravity of the missile. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walter HWK 109-500
The Walter HWK 109-500 was a Liquid-propellant rocket, liquid-fuelled rocket engine developed by Hellmuth Walter Kommanditgesellschaft, Walter in Germany during the World War II, Second World War. Description The 109-500 is a self-contained, modular monopropellant JATO, ''Starthilfe'' (take-off assist) engine in a pod, able to produce thrust for thirty seconds. After the fuel was expended, the pod was jettisoned and it returned to earth by parachute, with the parachute packed externally, onto the blunt forward end of the pod. The T-Stoff monopropellant, stored in the large spherical tank within the ''Starthilfe'' module's forward end, needed to react with a catalyst to provide the boosting thrust for an aircraft on takeoff - this Z-Stoff Sodium permanganate, sodium or Calcium permanganate, calcium-based, alkaline permanganate-compound (in an aqueous solution) catalyst was provided in a small tank above the reaction chamber just forward of the exhaust nozzle, with compressed a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T-Stoff
T-Stoff (; 'substance T') was a stabilised high test peroxide used in Nazi Germany, Germany during World War II. T-Stoff was specified to contain 80% (occasionally 85%) hydrogen peroxide (H2O2), remainder water, with traces (<0.1%) of stabilisers. Stabilisers used included 0.0025% phosphoric acid, a mixture of phosphoric acid, trisodium phosphate, sodium phosphate and Oxyquinoline, 8-oxyquinoline, and sodium stannate. Uses The decomposition of T-Stoff into hot steam and oxygen caused by the addition of the catalyst Z-Stoff (an aqueous solution of permanganates) was used to drive the split-tube steam catapults which launched the V-1 flying bomb. Similarly generated steam was used to drive the turbopump in the German V-2 rocket, V2 rocket, and the pumps in several other rocket engines. The turbopump was used to transport fuel and oxidizer liquids under pressure to the rocket engine of the V2. Another of T-Stoff's many uses was to be combined as the oxidizer, ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ministry Of Aviation (Nazi Germany)
The Ministry of Aviation (, abbreviated RLM) was a government department during the period of Nazi Germany (1933–45). It is also the original name of the Detlev-Rohwedder-Haus building on the Wilhelmstrasse in central Berlin, Germany, which houses the modern German Finance Ministry (). The Ministry was in charge of development and production of all aircraft developed, designed, and built in Germany during the existence of the Third Reich, overseeing all matters concerning both military and civilian designs – it handled military aviation matters as its top priority, particularly for the Luftwaffe. As was characteristic of government departments in the Nazi era, the Ministry was personality-driven and formal procedures were often ignored in favour of the whims of the Minister, '' Reichsmarschall'' Hermann Göring. As a result, early successes in aircraft development progressed only slowly and erratically during World War II. History The Ministry was formed on 27 April 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hellmuth Walter Kommanditgesellschaft
Hellmuth Walter Kommanditgesellschaft (HWK), Helmuth Walter Werke (HWM), or commonly known as the Walter-Werke, was a German company founded by Professor Hellmuth Walter to pursue his interest in engines using hydrogen peroxide as a propellant. Having experimented with torpedoes and submarines, Walter began to design rocket engines for aircraft and founded the HWK in Kiel in 1935. During World War II the HWK developed and built a variety of rocket engines for assisted take-off ( RATO), and guided missiles, before developing main propulsion engines for rocket-powered interceptor aircraft, notably the Messerschmitt Me 163 ''Komet'' and the Bachem Ba 349 ''Natter''. HWM designed the steam catapult that launched the V-1 flying bomb. The steam was generated through the combination of T-Stoff and Z-Stoff. The company was wound up in 1945 and Walter subsequently continued his work in the United States. See also * C-Stoff C-Stoff (; "substance C") was a Redox, reductant used i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypergolic Propellant
A hypergolic propellant is a rocket propellant combination used in a rocket engine, whose components spontaneously ignite when they come into contact with each other. The two propellant components usually consist of a fuel and an oxidizer. The main advantages of hypergolic propellants are that they can be stored as liquids at room temperature and that engines which are powered by them are easy to ignite reliably and repeatedly. Common hypergolic propellants are extremely toxic or corrosive, making them difficult to handle. In contemporary usage, the terms "hypergol" and "hypergolic propellant" usually mean the most common such propellant combination: dinitrogen tetroxide plus hydrazine. History The fact that turpentine may spontaneously combust when mixed with nitric acid was discovered as early as the late 17th century by Frederick Slare, but it remained a scientific curiosity for centuries until it was proposed to use it for rocket-assisted take off during WWII. In 1935 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
