GAS TURBINE ENGINES FOR MODEL AIRCRAFT BY KURT SCHRECKLING PDF

It most likely served no practical purpose, and was rather more of a curiosity; nonetheless, it demonstrated an important principle of physics that all modern turbine engines rely on. When the lamp is lit, the heated airflow rises and drives an impeller with horse-riding figures attached on it, whose shadows are then projected onto the outer screen of the lantern. His invention had most of the elements present in the modern day gas turbines. The turbine was designed to power a horseless carriage. The patent shows that it was a gas turbine and the drawings show it applied to a locomotive. Teleshov , a Russian aviation pioneer.

Author:Daijar Yozshugrel
Country:Nepal
Language:English (Spanish)
Genre:Science
Published (Last):9 September 2012
Pages:420
PDF File Size:1.3 Mb
ePub File Size:11.79 Mb
ISBN:119-3-61065-287-6
Downloads:74427
Price:Free* [*Free Regsitration Required]
Uploader:Dour



It most likely served no practical purpose, and was rather more of a curiosity; nonetheless, it demonstrated an important principle of physics that all modern turbine engines rely on. When the lamp is lit, the heated airflow rises and drives an impeller with horse-riding figures attached on it, whose shadows are then projected onto the outer screen of the lantern.

His invention had most of the elements present in the modern day gas turbines. The turbine was designed to power a horseless carriage. The patent shows that it was a gas turbine and the drawings show it applied to a locomotive. Teleshov , a Russian aviation pioneer.

This principle of propulsion is still of some use. His design used a small turbine wheel, driven by exhaust gases, to turn a supercharger. Working testbed designs of axial turbines suitable for driving a propellor were developed by the Royal Aeronautical Establishment , thereby proving the efficiency of aerodynamic shaping of the blades in The first successful use of his engine occurred in England in April Following the gas turbine principle, the steam evaporation tubes are arranged within the gas turbine combustion chamber; the first Velox plant was erected in Mondeville, Calvados, France.

This marks the beginning of the reign of gas turbines in the sky. Together, these make up the Brayton cycle. Brayton cycle In a real gas turbine, mechanical energy is changed irreversibly due to internal friction and turbulence into pressure and thermal energy when the gas is compressed in either a centrifugal or axial compressor.

Heat is added in the combustion chamber and the specific volume of the gas increases, accompanied by a slight loss in pressure. During expansion through the stator and rotor passages in the turbine, irreversible energy transformation once again occurs. Fresh air is taken in, in place of the heat rejection. If the engine has a power turbine added to drive an industrial generator or a helicopter rotor, the exit pressure will be as close to the entry pressure as possible with only enough energy left to overcome the pressure losses in the exhaust ducting and expel the exhaust.

For a turboprop engine there will be a particular balance between propeller power and jet thrust which gives the most economical operation. In a turbojet engine only enough pressure and energy is extracted from the flow to drive the compressor and other components. The remaining high-pressure gases are accelerated through a nozzle to provide a jet to propel an aircraft. The smaller the engine, the higher the rotation rate of the shaft s must be to attain the required blade tip speed.

Blade-tip speed determines the maximum pressure ratios that can be obtained by the turbine and the compressor. This, in turn, limits the maximum power and efficiency that can be obtained by the engine.

In order for tip speed to remain constant, if the diameter of a rotor is reduced by half, the rotational speed must double. For example, large jet engines operate around 10,, rpm, while micro turbines spin as fast as , rpm. This, in turn, can translate into price.

More advanced gas turbines such as those found in modern jet engines or combined cycle power plants may have 2 or 3 shafts spools , hundreds of compressor and turbine blades, movable stator blades, and extensive external tubing for fuel, oil and air systems; they use temperature resistant alloys, and are made with tight specifications requiring precision manufacture.

All this often makes the construction of a simple gas turbine more complicated than a piston engine. Moreover, to reach optimum performance in modern gas turbine power plants the gas needs to be prepared to exact fuel specifications.

Fuel gas conditioning systems treat the natural gas to reach the exact fuel specification prior to entering the turbine in terms of pressure, temperature, gas composition, and the related wobbe-index. The primary advantage of a gas turbine engine is its power to weight ratio. Thrust bearings and journal bearings are a critical part of a design. They are hydrodynamic oil bearings or oil-cooled rolling-element bearings.

Higher operating temperatures are continuously sought in order to increase efficiency, but come at the cost of higher creep rates. Several methods have therefore been employed in an attempt to achieve optimal performance while limiting creep, with the most successful ones being high performance coatings and single crystal superalloys. Protective coatings provide thermal insulation of the blade and offer oxidation and corrosion resistance.

Using TBCs limits the temperature exposure of the superalloy substrate, thereby decreasing the diffusivity of the active species typically vacancies within the alloy and reducing dislocation and vacancy creep. The Al from the bond coats forms Al2O3 on the TBC-bond coat interface which provides the oxidation resistance, but also results in the formation of an undesirable interdiffusion ID zone between itself and the substrate. The addition of these elements reduces the diffusion of the gamma prime phase, thus preserving the fatigue resistance, strength, and creep resistance.

Due to the lack of grain boundaries, single crystals eliminate Coble creep and consequently deform by fewer modes - decreasing the creep rate.

Care needs to be taken in order to optimize the design parameters to limit high temperature creep while not decreasing low temperature yield strength. Jet engines[ edit ] typical axial-flow gas turbine turbojet, the J85 , sectioned for display. Flow is left to right, multistage compressor on left, combustion chambers center, two-stage turbine on right Airbreathing jet engines are gas turbines optimized to produce thrust from the exhaust gases, or from ducted fans connected to the gas turbines.

Gas turbines are also used in many liquid fuel rockets , where gas turbines are used to power a turbopump to permit the use of lightweight, low-pressure tanks, reducing the empty weight of the rocket. Turboprop engines[ edit ] A turboprop engine is a turbine engine that drives an aircraft propeller using a reduction gear. Turboprop engines are used on small aircraft such as the general-aviation Cessna Caravan and Embraer EMB Tucano military trainer, medium-sized commuter aircraft such as the Bombardier Dash 8 and large aircraft such as the Airbus AM transport and the year-old Tupolev Tu strategic bomber.

Aeroderivative gas turbines[ edit ] Diagram of a high-pressure film-cooled turbine blade Aeroderivatives are also used in electrical power generation due to their ability to be shut down and handle load changes more quickly than industrial machines. They are also used in the marine industry to reduce weight. In its most straightforward form, these are commercial turbines acquired through military surplus or scrapyard sales, then operated for display as part of the hobby of engine collecting.

The simplest form of self-constructed gas turbine employs an automotive turbocharger as the core component. A combustion chamber is fabricated and plumbed between the compressor and turbine sections. Several small companies now manufacture small turbines and parts for the amateur. Most turbojet-powered model aircraft are now using these commercial and semi-commercial microturbines, rather than a Schreckling-like home-build.

They supply: compressed air for air conditioning and ventilation, compressed air start-up power for larger jet engines , mechanical shaft power to a gearbox to drive shafted accessories or to start large jet engines, and electrical, hydraulic and other power-transmission sources to consuming devices remote from the APU. Industrial gas turbines for power generation[ edit ] GE H series power generation gas turbine: in combined cycle configuration, its highest thermal efficiency is They are also much more closely integrated with the devices they power— often an electric generator —and the secondary-energy equipment that is used to recover residual energy largely heat.

They range in size from portable mobile plants to large, complex systems weighing more than a hundred tonnes housed in purpose-built buildings. However, it may be cheaper to buy electricity than to generate it.

Therefore, many engines are used in CHP Combined Heat and Power configurations that can be small enough to be integrated into portable container configurations.

Gas turbines can be particularly efficient when waste heat from the turbine is recovered by a heat recovery steam generator to power a conventional steam turbine in a combined cycle configuration. They can also be run in a cogeneration configuration: the exhaust is used for space or water heating, or drives an absorption chiller for cooling the inlet air and increase the power output, technology known as Turbine Inlet Air Cooling. Another significant advantage is their ability to be turned on and off within minutes, supplying power during peak, or unscheduled, demand.

Since single cycle gas turbine only power plants are less efficient than combined cycle plants, they are usually used as peaking power plants , which operate anywhere from several hours per day to a few dozen hours per year—depending on the electricity demand and the generating capacity of the region.

In areas with a shortage of base-load and load following power plant capacity or with low fuel costs, a gas turbine powerplant may regularly operate most hours of the day. The power range varies from 1 megawatt up to 50 megawatts. The majority of installations are used within the oil and gas industries. Oil and gas platforms require these engines to drive compressors to inject gas into the wells to force oil up via another bore, or to compress the gas for transportation.

They are also often used to provide power for the platform. These platforms do not need to use the engine in collaboration with a CHP system due to getting the gas at an extremely reduced cost often free from burn off gas. The same companies use pump sets to drive the fluids to land and across pipelines in various intervals. Compressed air energy storage[ edit ] Main article: Compressed air energy storage One modern development seeks to improve efficiency in another way, by separating the compressor and the turbine with a compressed air store.

In a conventional turbine, up to half the generated power is used driving the compressor. In a compressed air energy storage configuration, power, perhaps from a wind farm or bought on the open market at a time of low demand and low price, is used to drive the compressor, and the compressed air released to operate the turbine when required.

Turboshaft engines[ edit ] Turboshaft engines are often used to drive compression trains for example in gas pumping stations or natural gas liquefaction plants and are used to power almost all modern helicopters. The primary shaft bears the compressor and the high-speed turbine often referred to as the Gas Generator , while a second shaft bears the low-speed turbine a power turbine or free-wheeling turbine on helicopters, especially, because the gas generator turbine spins separately from the power turbine.

This arrangement is used to increase power-output flexibility with associated highly-reliable control mechanisms. Various successors have made good progress in the refinement of this mechanism.

Owing to a configuration that keeps heat away from certain bearings, the durability of the machine is improved while the radial turbine is well matched in speed requirement. External combustion has been used for the purpose of using pulverized coal or finely ground biomass such as sawdust as a fuel. In the indirect system, a heat exchanger is used and only clean air with no combustion products travels through the power turbine.

The thermal efficiency is lower in the indirect type of external combustion; however, the turbine blades are not subjected to combustion products and much lower quality and therefore cheaper fuels are able to be used.

When external combustion is used, it is possible to use exhaust air from the turbine as the primary combustion air. This effectively reduces global heat losses, although heat losses associated with the combustion exhaust remain inevitable.

Closed-cycle gas turbines based on helium or supercritical carbon dioxide also hold promise for use with future high temperature solar and nuclear power generation.

In surface vehicles[ edit ] MAZ , a Transporter erector launcher with a Turbine-electric transmission Gas turbines are often used on ships , locomotives , helicopters , tanks , and to a lesser extent, on cars, buses, and motorcycles.

A key advantage of jets and turboprops for airplane propulsion - their superior performance at high altitude compared to piston engines, particularly naturally aspirated ones - is irrelevant in most automobile applications. Their power-to-weight advantage, though less critical than for aircraft, is still important. Gas turbines offer a high-powered engine in a very small and light package. However, they are not as responsive and efficient as small piston engines over the wide range of RPMs and powers needed in vehicle applications.

In series hybrid vehicles , as the driving electric motors are mechanically detached from the electricity generating engine, the responsiveness, poor performance at low speed and low efficiency at low output problems are much less important. The turbine can be run at optimum speed for its power output, and batteries and ultracapacitors can supply power as needed, with the engine cycled on and off to run it only at high efficiency.

The emergence of the continuously variable transmission may also alleviate the responsiveness problem. Turbines have historically been more expensive to produce than piston engines, though this is partly because piston engines have been mass-produced in huge quantities for decades, while small gas turbine engines are rarities; however, turbines are mass-produced in the closely related form of the turbocharger. The centripetal turbine wheel drives a centrifugal compressor wheel through a common rotating shaft.

It mainly serves as a power recovery device which converts a great deal of otherwise wasted thermal and kinetic energy into engine boost. While the turbocharger is a pressure turbine, a power recovery turbine is a velocity one.

Passenger road vehicles cars, bikes, and buses [ edit ] A number of experiments have been conducted with gas turbine powered automobiles , the largest by Chrysler. Concept cars[ edit ] The Rover JET1 The first serious investigation of using a gas turbine in cars was in when two engineers, Robert Kafka and Robert Engerstein of Carney Associates, a New York engineering firm, came up with the concept where a unique compact turbine engine design would provide power for a rear wheel drive car.

HARWOOD NUSS PDF

Gas turbine

Career[ edit ] His design was constructed using hand tools, and has a wooden compressor and a bent metal gas turbine. It was fitted into a radio-controlled aircraft that flew successfully. He won various prizes and wrote books about this field of research. Jet engines following his design are designated with a K, and J for Jesus Artes — his co-developer for example KJ66 Gas turbine Scale jet engines Years later and being retired he became an innovative well known developer for high end amateur astronomy components in the field of amateur telescope making ATM. Having worked in his professional career as a physicist and measurement engineer in a German DAX -Company Kurt Schreckling introduced advanced opportunities and unorthodox ways to optimize and measure telescopes for ambitious amateurs on a high quality level regarding surface quality, light weight construction while permanently compensating different optical aberrations. His ideas for improving telescopes and their optical perfection have become legendary in the German-speaking countries in the amateur telescope maker scene.

CASIO FX-82MS TRICKS PDF

Kurt Schreckling

.

KRIMINALGESCHICHTE DES CHRISTENTUMS PDF

Gas Turbine Engines for Model Aircraft Book – by Kurt Schreckling

.

Related Articles