Showing papers on "Afterburner published in 2015"

Synthesis Gas Afterburner Based on an Injector Type Plasma-Assisted Combustion System

Abstract: This paper presents the results of theoretical and experimental investigations of a developed synthesis gas afterburner based on an injector type plasma-assisted combustion system. The basic overall dimensions of the afterburner with the injecting device are determined. The design concept can provide higher performance, wider turndown ratios, more efficient synthesis gas combustion, and satisfaction of major ecological requirements.

Experimental investigations on combustion characteristics of a cavity pilot augmentor of the turbine-based combined cycle engine

Abstract: A cavity flame holder has been a very promising novel concept to be applied to the augmentor of a turbine-based combined cycle (TBCC) engine as it offers improvements in ignition performance, altitude relight, lean blowout limit, operating range, as well as combustion efficiency compared to conventional bluff body flame holders. The present paper describes the detailed designs of a cavity pilot augmentor and provides a laboratory-scale test rig. A series of experiments has been conducted to investigate the combustion characteristics of the test rig under atmospheric pressure. Experimental results show that for the bypass inlet temperature 343–473?K and inlet Mach number 0.25–0.40, ignition equivalence ratio and ignition pressure oscillation obtained is between 0.94–1.72 and 1.1–2.4% respectively, and lean blowout equivalence is between 0.42 and 0.92, indicating good ignition and lean blowout performances; as the total fuel-to-air ratio increases, the combustion efficiency decreases in the main at both afterburner operating mode and ramjet operating mode, while the increase of the bypass inlet Mach number or temperature is beneficial to high combustion efficiency, especially as inlet temperature over 423?K, and the combustion efficiency got in present experiment is between 70% and 95%. This paper demonstrates the feasibility for the cavity pilot flame holder to be applied to a realistic augmentor of TBCC engine preliminarily and provides reference for TBCC augmentor design.

Analysis of Test-Cell Emission Measurements of Newly Overhauled Turbofan Engines

Abstract: In this study, the gaseous emissions of newly overhauled CFM56-3B1 and -3B2 series turbofan engines are measured in a test-cell environment during typical functional and performance test procedures. The measured emissions are carbon dioxide, carbon monoxide, total hydrocarbons, and nitrogen oxides. A unique emissions sample system was used, where the sample probe was located behind the final stage of the low-pressure turbine rotor, avoiding having any bypass air or ambient air in the emissions. The emission production patterns are evaluated with the engine parameters of fan speed, fuel flow, and exhaust gas temperatures. Characterizing the concentrations and emission indices at stable power settings, the results also contribute to arguments on the effects of hot and cold idles, probe locations, and NO2/NOx ratios. Even though the present study differs from that of the International Civil Aviation Organization Aircraft Engine Emission Database in several respects, a comparison reveals relatively good agree...

Hovercar and control system thereof

Abstract: The invention discloses a hovercar and a control system thereof. The hovercar comprises a main engine (10), a land travelling mechanism (30), flying wings (40) which can extend outward from the body of the hovercar and a thrust deviator (50) for changing the flight thrust, wherein the main engine (10) is a small-scale turbofan engine or a small-scale turbojet engine; an exhaust system (60) which can be opened or closed is arranged between a tail exhaust nozzle (18) and an afterburner (19) of the main engine (10), the main engine (10) is provided with a power takeoff (11), and the land travelling mechanism (30) is connected to the power takeoff (11). The hovercar has favorable flexibility of travelling on land and favorable drivability.

Furnace for combustion of solid fuel (versions)

Abstract: FIELD: power industrySUBSTANCE: furnace for combustion of solid fuel includes a housing with a loading hopper for solid fuel, a combustion chamber with a grating, an air supply device, an afterburner chamber with an opening into it; the combustion chamber has a movable horizontal grating moved throughout the height, a movable and turning inclined rear grating and a movable and turning inclined guide plate The air supply device is made in the form of a pipe so that flow of air and combustible gases before they enter the afterburner chamber is directed towards to each other as per a counter-flow circuitEFFECT: invention allows improving economy and efficiency of operation of a furnace for combustion of solid fuel due to involvement in an active combustion process of the required fuel layer and control of dimensions of fire bed surface on grate bars4 cl, 2 dwg

Digital electronic control system with built-in complete thermo- and gas-dynamic mathematical model of gas turbine engine, and aircraft gas turbine engine

Abstract: FIELD: engines and pumps.SUBSTANCE: group of inventions relates to aircraft gas turbine engines (GTE). Improvement of quality and reliable control of GTE under actual operating conditions due to "virtual engine" software built in GTE control system and providing online calculation of non-measured GTE parameters in steady-state and transient modes of its operation in full range of their change by means of GTE thermo- and gas-dynamic mathematical model contained in it, engine control as per these design parameters, self-identification of the engine model, as well as replacement of engine parameters used for control of measured values at failure of the corresponding sensors with their design values determined by means of the thermo- and gas-dynamic mathematical model. For that purpose, a digital electronic control system of an aircraft gas turbine engine is proposed, which includes a built-in complete thermo- and gas-dynamic mathematical model of a gas turbine engine, consisting of "virtual engine" software for on-line calculation of values of internal parameters of the operating process and performance characteristics of the engine, which are not accessible for measurement, such as: engine thrust R, temperature T*of gas in a combustion chamber, margins of gas-dynamic stability of compressor ?Ks, excess air coefficient in the main combustion chamber ?and afterburner ?, temperature Ti, pressure Pi and air (gas) flow rate Gi in the main cross sections (i - cross section index) of the engine.EFFECT: improvement of quality and reliable control of GTE under real operating conditions.6 cl, 9 dwg

Control over gas turbine engine with afterburner combustion chamber

Abstract: FIELD: engines and pumps.SUBSTANCE: invention can be used in electronic hydro mechanical ACS of multimode gas turbine engines with afterburner combustion chamber in operation at training conditions to ensure reliable fuel firing at actuation of afterburning from lower modes of cold engine (below "Maximum" mode). By signal of afterburner chamber firing device an in-engine parameter magnitude is increased to adjust fuel feed to the main combustion chamber to preset level. After firing in afterburner chamber, fuel feed rate in is decreased by the same amount.EFFECT: higher efficiency.1 dwg

Study on numerical simulation of flowfield in afterburner for ducted rocket

Abstract: Ducted rocket has been widely concerned on account of its high specific impulse, combustion stability and convenient maintenance which mixes the exhaust from a fuel gas generator with air from air inlet, and burns to produce thrust. It is necessary to establish two-dimensional or three-dimensional numerical models based on computational fluid dynamics to study on the flowfield in afterburner which is the key of ducted rocket because of expensive experiments, which is aimed at providing theoretical foundation for ducted rocket’s development. In this paper, the gas-phase turbulent combustion process in afterburner with dual inlet three-dimensional mode was simulated numerically by solving Favre-averaged compressible turbulent N-S equations, the renormalization group (RNG) k-e turbulence model was applied to simulate the turbulent flow, and Eddy-Dissipation Model (EDM) was applied to simulate gas combustion. Through simulation, situation analysis of flowfield in afterburner was done, and the influence of mixing combustion on afterburner was studied by taking air inlet angles and air-fuel ratio into account respectively. The results indicate that the distribution of temperature in afterburner is nonuniform, the backflow and axial swirl produced by gas mixing have an important influence on afterburner combustion. As air inlet angle is increased, the intensity of gas mixing is enhanced which is beneficial for afterburner combustion. That increasing air-fuel ratio is able to strength contact of oxygen with fuel gas, so that more fuel gas is consumed in the same location which is more beneficial for afterburner combustion.

Exploring the Impact of Elevated Turbine Blade Cooling Effectiveness and Turbine Material Temperatures on Gas Turbine Engine Performance and Cost

Abstract: Since the 1950’s, the turbine inlet temperatures of gas turbine engines have been steadily increasing as engine designers have sought to increase engine thrust-to-weight and reduce fuel consumption. In turbojets and low-bypass turbofan engines, increasing the turbine inlet temperature boosts specific thrust, which in some cases can support supersonic flight without the use of an afterburner. In high-bypass gas turbine engines, increasing the turbine inlet temperature makes possible higher bypass ratios and overall pressure ratios, both of which reduce specific fuel consumption. Increased turbine inlet temperatures, without sacrificing blade life, have been made possible through advances in blade cooling effectiveness and high-temperature turbine blade materials. Investigating the impact of higher turbine inlet temperatures and the corresponding cooling air flow rates on specific thrust, specific fuel consumption, and engine development cost is the subject of this paper. A physics-based cooling effectiveness correlation is presented for linking turbine inlet temperature to cooling flow fraction. Two cases are considered: 1) a low-bypass, mixed-exhaust, non-afterburning turbofan engine intended to support supercruising at Mach 1.5 and 2) a high-bypass, unmixed-exhaust turbofan engine intended to support highly efficient, long range flight at Mach 0.8. For each of these two cases, both baseline and enhanced cooling effectiveness values as well as both baseline and elevated turbine blade material temperatures are considered. Comparing these cases will ensure that students taking courses in preliminary engine design understand why huge research investments continue to be made in turbine blade cooling and advanced, high-temperature turbine blade material development.© 2015 ASME

Fuel-Rich Combustion Characteristic of a Combined Gas Generator

Abstract: In this study, a combined hybrid rocket system is newly introduced which has characteristics of both gas generators and afterburner type hybrid rockets. In particular, a combined gas generator utilizing solid fuel and liquid/gas oxidizer was designed as a primary combustor of the system. Combustion tests were carried out with various equivalence ratio affected by parameters such as fuel length, oxidizer flow rate, fuel port diameter and fuel type. In general, fuel-rich gas generator produces low combustion gas temperature to meet the temperature requirement and the target temperature was transiently set less than 1600 K. Since it was found that controlling parameters showed limited effects on the change of equivalence ratio, mixture of and as an oxidizer was additionally introduced. As a result, a combined gas generator successfully produced combustion gas temperature of less than 1600 K Future studies will carry out more combustion tests to attain fuel-rich combustion gas temperature less than 1200 K, which was a temperature requirement of a gas generator system in the previous studies.

A Study of Aero-Engine Supersonic Cruise Performance Seeking Control

Abstract: In order to solve the problem of performance seeking control in the aero-engine supersonic cruise without afterburner,a new optimization program by sequential quadratic programming(SQP) with five variables is proposed,which is by means of adding a new variable called inlet-bleeding coefficient to the conventional optimizing variables made up of guided vanes of fan and compressor,fuel flow,nozzle throat area. Better effectiveness is certificated by the simulation results via the new optimization program than the conventional SQP with four variables in the modes of the maximum thrust mode,the minimum fuel-consumption mode and the minimum turbine temperature mode. The installed thrust is enhanced by 7.5% in the maximum thrust mode,4.6%drop of fuel-consumption in the minimum fuel-consumption mode,1.5% drop of turbine blade temperature in the minimum turbine temperature mode. Meanwhile,a new type of engine adaptive model is developed to meet the adaptive requirements of onboard model which is improved by adding the output error feedback to the Kalman filter. The new optimization program with five variables also shows an obvious advantage in global optimization while performance degradation happens.

Characteristics of flow and thrust variations in a jet engine with a variable area nozzle

Abstract: A numerical analysis of the internal flow field in an exhaust converging-diverging nozzle of a jet engine has been carried out. Variable area nozzle is required in a jet engine for optimal expansion and adjusting back pressure in the engine when the afterburner is operated. Steady-state and transient analyses are carried out for each condition with and without afterburner operation and as a function of the location of the nozzle flap. For a baseline power condition, mixture composition of combustion products is calculated by the chemical equilibrium analysis and the cold flow analysis is carried out based on the mixture composition. For the afterburner operating condition, additional fuel is injected from the inlet boundary and numerical analyses of reactive flow fields are carried out. With variable area nozzle adopted, combustion fields are variable in time, leading to periodically variable thrust. When nozzle flap is in a closed state, nozzle internal pressure and temperature are increased upon the afterburner operation and moment of a force at the pivot point is increased as well. These undesirable phenomena can be solved by control of a variable area nozzle. And, thrust level is also maximized by nozzle variation. During nozzle variation, unsteadiness effect is observed because of response lag of internal flow to nozzle variation. Both the design pressure and the optimum expansion of the nozzle can be attained by adopting the independent operation of a variable area nozzle.

Solid fuel gas-turbine plant

Abstract: FIELD: power industry.SUBSTANCE: invention relates to power industry. The solid fuel tad-turbine plant containing compressor, turbine, payload located on same shaft, solid fuel combustion chamber made as installed in series gasifier, afterburner and mixer, an heat-exchanger. The compressor is made with atmosphere air inlet and outlet, connected to input of cold loop of the heat-exchanger. Output of cold loop of the heat-exchanger is connected with the turbine input, turbine output is connected with air supply line to combustion chamber made as three pipelines with chokes installed in air supply pipelines to mixer and afterburner. The chokes installation in air supply pipelines to mixer and afterburner determines minimum hydraulic losses via the gasifier, thus ensuring maximum efficiency of the plant.EFFECT: invention reduces losses in gas-turbine tract, excludes abrasive wear-out of the flow part of the plant, and increases of the entire plant efficiency.3 cl, 1 dwg

Method of condition monitoring and maintenance of gas turbine engine during its operation

Abstract: FIELD: engines and pumps.SUBSTANCE: method comprises the fuel pressure measurement in the afterburner manifold of the engine which is performed periodically, comparison of the obtained value of fuel pressure in the afterburner manifold of the engine with the maximum allowable one, which is pre-set for this type of engines, and at excess of the latter - cleaning of the afterburner collector and nozzles. Medium from its internal cavity is evacuated by means of evacuation device, for example a vacuum pump, and the pressure created by the evacuation device is changed periodically. Medium is passed through the reference filter which is periodically checked for particles of coke deposits in it, and by their presence in the filter the level of the manifold cleaning is obvious. The manifold cavity is filled with flushing liquid and after holding it is removed from the manifold internal cavity towards the direction, opposite to fuel supply, meanwhile for flushing liquid it is possible to use the flushing liquid TSR-5050 or ZOK-27. The cleaning on the working engine is performed for this purpose the engine is brought to the low acceleration mode, then by increase of rotor rotation speed they are brought to the maximum unboosted mode, maintained in it and the rotor rotation speed reduced down to the low acceleration mode. The maximum allowable value of pressure in the manifold of the afterburner is obvious by pressure in the manifold at minimum allowable fuel consumption through the clogged fuel manifold, at which normal functioning of the afterburner chamber without blackout and loss of traction is ensured.EFFECT: improvement of quality of cleaning of manifold and nozzles without engine disassembly.8 cl, 1 dwg

Multi-reformable fuel delivery systems and methods for fuel cells

Abstract: The present teachings provide multi-reformable fuel delivery systems and methods that can deliver, without the use of a liquid pump, any hydrocarbon fuel, i.e., a liquid or gaseous reformable fuel, for example, to at least one of a reformer, a vaporizer, a fuel cell stack, an afterburner and other assemblies and components of a fuel cell unit or system, More specifically, gas pressure can be used to control and deliver gaseous reformable fuels and/or liquid reformable fuels in the delivery systems and methods of the present teachings. The delivery systems and methods also can apply to the delivery of a liquid reactant such as water and gaseous reactants such as an oxygen-containing gas (e.g., air) and steam.

An Experimental Investigation into the Performance of a Novel-Integrated Afterburner-Reformer in a 1 kw Solid Oxide Fuel Cell System

Abstract: In traditional Solid Oxide Fuel Cell (SOFC) systems, the anode and cathode off-gases are combusted in an afterburner and the flue gas is then used to provide the thermal energy required for hydrogen reforming. However, significant heat losses occur in the piping between the afterburner and the reformer, and thus the overall efficiency of the SOFC system is reduced. Accordingly, the present study proposes a novel-integrated afterburner-reformer, which not only improves the system efficiency, but also reduces the required afterburner operating temperature. The experimental results show that the combined H2 and CO content of the reformate gas is approximately 80%. In other words, the reforming performance of the proposed afterburner-reformer is comparable with that of a conventional electrically-heated reformer.

혼합식 가스발생기의 연료과농 연소특성

Abstract: In this study, a combined hybrid rocket system is newly introduced which has characteristics of both gas generators and afterburner type hybrid rockets. In particular, a combined gas generator utilizing solid fuel and liquid/gas oxidizer was designed as a primary combustor of the system. Combustion tests were carried out with various equivalence ratio affected by parameters such as fuel length, oxidizer flow rate, fuel port diameter and fuel type. In general, fuel-rich gas generator produces low combustion gas temperature to meet the temperature requirement and the target temperature was transiently set less than 1600 K. Since it was found that controlling parameters showed limited effects on the change of equivalence ratio, mixture of O₂ and N₂ as an oxidizer was additionally introduced. As a result, a combined gas generator successfully produced combustion gas temperature of less than 1600 K Future studies will carry out more combustion tests to attain fuel-rich combustion gas temperature less than 1200 K, which was a temperature requirement of a gas generator system in the previous studies.