Energy Efficient Engine (E3) controls and accessories detail design report

An Energy Efficient Engine program has been established by NASA to develop technology for improving the energy efficiency of future commercial transport aircraft engines. As part of this program, a new turbofan engine was designed. This report describes the fuel and control system for this engine. The system design is based on many of the proven concepts and component designs used on the General Electric CF6 family of engines. One significant difference is the incorporation of digital electronic computation in place of the hydromechanical computation currently used

Energy Efficient Engine: Control system component performance report

An Energy Efficient Engine (E3) program was established to develop technology for improving the energy efficiency of future commercial transport aircraft engines. As part of this program, General Electric designed and tested a new engine. The design, fabrication, bench and engine testing of the Full Authority Digital Electronic Control (FADEC) system used for controlling the E3 Demonstrator Engine is described. The system design was based on many of the proven concepts and component designs used on the General Electric family of engines. One significant difference is the use of the FADEC in place of hydromechanical computation currently used

Propulsion controls

Increased system requirements and functional integration with the aircraft have placed an increased demand on control system capability and reliability. To provide these at an affordable cost and weight and because of the rapid advances in electronic technology, hydromechanical systems are being phased out in favor of digital electronic systems. The transition is expected to be orderly from electronic trimming of hydromechanical controls to full authority digital electronic control. Future propulsion system controls will be highly reliable full authority digital electronic with selected component and circuit redundancy to provide the required safety and reliability. Redundancy may include a complete backup control of a different technology for single engine applications. The propulsion control will be required to communicate rapidly with the various flight and fire control avionics as part of an integrated control concept

Hydraulic Modeling of a Mixed Water Level Control Hydromechanical Gate

This article describes the hydraulic behavior of a mixed water level control hydromechanical gate present in several irrigation canals. The automatic gate is termed "mixed" because it can hold either the upstream water level or the downstream water level constant according to the flow conditions. Such a complex behavior is obtained through a series of side tanks linked by orifices and weirs. No energy supply is needed in this regulation process. The mixed flow gate is analyzed and a mathematical model for its function is proposed, assuming the system is at equilibrium. The goal of the modeling was to better understand the mixed gate function and to help adjust their characteristics in the field or in a design process. The proposed model is analyzed and evaluated using real data collected on a canal in the south of France. The results show the ability of the model to reproduce the function of this complex hydromechanical system. The mathematical model is also implemented in software dedicated to hydraulic modeling of irrigation canals, which can be used to design and evaluate management strategies

Regularities of hydromechanical amber extraction from sandy deposits

Purpose is to analyze the efficiency of hydromechanical amber extraction from sandy deposits relying upon the determined regularities concerning the effect of parameters while carrying out a series of laboratory tests and full-scale experiments. Methods. Laboratory tests and full-scale experiments (Volodymyrets amber-bearing deposit, village of Berezhnytsia) were carried out to analyze effect of the parameters of a hydromechanical technique on the velocity of amber extraction. The experiments also involved studies of occurrence medium; in this context, boiling process was modeled; and factors and parameters effecting suspense medium formation were researched. Methods of mathematical statistics were applied to obtain dependences describing mining parameters effect on amber extraction velocity. Findings. Basic parameters of hydromechanical technique, effecting amber extraction velocity, have been determined. Efficient values of air supply to provide maximum velocity of amber floating have been identified. Mathematical dependences, determining amber floating velocity depending upon air supply and mechanical effect frequency, have been obtained. In this context, amber production capacity is 90 to 95%. Basic parameters effecting amber mining (i.e. environmental density; amplitude of oscillations and their frequency; and water and air supply to sandy deposit of amber-bearing sand) have been defined. Originality. It has been first proved that amber floating velocity is of polynomial nature dependence upon environmental density where extremum is with 0.004 – 0.006 m3/h air supply value; amber extraction experiences 2 – 3 times intensification, if environmental density (ρc) is 1670 – 1750 kg/m3, oscillation frequency is 26 – 36 Hz, amplitude is A = 1.0 – 2.4 mm, and air supply is qa = 0.004 – 0.006 m3/h. In this context, amber floating (v) is 0.09 – 0.12 m/s. If air supply is more than qa = 0.020 m3/h, amber extraction process stops. It has been first obtained polynomial dependence of amber flotation on oscillation frequency of operating device as well as on air supply to rock mass. Practical implications. The determined regularities of hydromechanical amber extraction from amber-bearing sand help make calculations, and select facilities for hydromechanical amber mining.Мета. Дослідження ефективності процесу гідромеханічного вилучення бурштину з піщаних покладів на основі встановлених закономірностей впливу параметрів шляхом проведення серії лабораторних та натурних експериментів. Методика. Експериментальним шляхом в лабораторних та польових умовах (Володимирецьке бурштино-вмісне родовище, с. Бережниця) проведено дослідження впливу параметрів гідромеханічного способу вилучення на швидкість підняття бурштину. При проведенні експериментальних досліджень вивчалось середовище залягання, при цьому проводилось моделювання процесу кипіння й дослідження факторів і параметрів, що впливають на створення суспензного середовища. Із використанням методів математичної статистики отримано залежності, що описують вплив параметрів вилучення на швидкість підняття бурштину. Результати. Визначено основні параметри гідромеханічного методу, що впливають на швидкість вилучення бурштину. Встановлено раціональні значення величини подачі повітря для забезпечення максимальної швидкості спливання бурштину. Отримано математичні залежності, що визначають швидкість спливання залежно від по-дачі повітря та частоти механічного впливу, при цьому рівень видобутку бурштину сягає 90 – 95%. Визначені основні параметри, які впливають на інтенсивність підняття бурштину на денну поверхню, – густина середовища, амплітуда та частота коливань, подача води й повітря у піщане родовище бурштиновмісного піску. Наукова новизна. Вперше доведено, що швидкість спливання бурштину має поліноміальний характер залежності від густини середовища з екстремумом при величині подачі повітря 0.004 – 0.006 м3/год, а вилучення бурштину інтенсифікується у 2 – 3 рази при густині робочого середовища (ρc) 1670 – 1750 кг/м3, частоті коливання 26 – 36 Гц, амплітуді А = 1.0 – 2.4 мм, подачі повітря qa = 0.004 – 0.006 м3/год, при цьому швидкість спливання бурштину (v) рівна 0.09 – 0.12 м/с, а при збільшенні подачі повітря понад 0.020 м3/год процес вилучення бурштину припиняється. Вперше отримано поліноміальну залежність швидкості спливання бурштину від частоти коливань робочого органу та подачі повітря в масив. Практична значимість. Визначені закономірності гідромеханічного вилучення бурштину із бурштиновмісних пісків дозволяють проводити розрахунок та обирати обладнання для проведення гідромеханічного видобутку бурштину.Цель. Исследование эффективности процесса гидромеханического извлечения янтаря из песчаных залежей на основе установленных закономерностей влияния параметров путем проведения серии лабораторных и натурных экспериментов. Методика. Экспериментальным путем в лабораторных и полевых условиях (Владимирецкое янтарное месторождение, с. Бережница) проведено исследование влияния параметров гидромеханического способа извлечения на скорость всплытия янтаря. При проведении экспериментальных исследований изучалась среда залегания, при этом проводилось моделирование процесса кипения и исследование факторов и параметров, влияющих на создание суспензионной среды. С использованием методов математической статистики получены зависимости, описывающие влияние параметров извлечения на скорость всплытия янтаря. Результаты. Определены основные параметры гидромеханического способа, влияющие на скорость извлечения янтаря. Установлены рациональные значения величины подачи воздуха для обеспечения максимальной скорости всплытия янтаря. Получены математические зависимости, определяющие скорость всплытия в зависимости от подачи воздуха и частоты механического воздействия, при этом уровень добычи янтаря достигает 90 – 95%. Определены основные параметры, влияющие на интенсивность всплытия янтаря на дневную поверхность, – плотность среды, амплитуда и частота колебаний, подача воды и воздуха в песчаное месторождение янтарного песка. Научная новизна. Впервые доказано, что скорость всплытия янтаря имеет полиномиальный характер зависимости от плотности среды с экстремумом при величине подачи воздуха 0.004 – 0.006 м3/ч, а извлечение янтаря интенсифицируется в 2 – 3 раза при плотности рабочей среды (ρc) 1670 – 1750 кг/м3, частоте колебания 26 – 36 Гц, амплитуде А = 1.0 – 2.4 мм, подачи воздуха qa = 0.004 – 0.006 м3/ч, при этом скорость всплытия янтаря (v) равна 0.09 – 0.12 м/с, а при увеличении подачи воздуха более 0.020 м3/час процесс извлечения янтаря завершается. Впервые получена полиномиальная зависимость скорости всплытия янтаря от частоты колебаний рабочего органа и от подачи воздуха в массив. Практическая значимость. Установленные закономерности гидромеханического извлечения янтаря с янтарных песков позволяют производить расчет и выбирать оборудование для проведения гидромеханической добычи янтаря.The studies have been carried out on the basis of the National University of Water and Environmental Engineering (town of Rivne), and with the participation of the experts from “Ukrainska Heolohichna Kompania” SE (Volyn Surveying Company, town of Kovel). The authors express thanks to a Vice-Rector for Research of the National University of Water and Environmental Engineering, Doctor of Ecological Sciences N.B. Savina for the opportunity to perform the research using laboratory equipment of the University, and to the authorities of “Ukrainska Heolohichna Kompania” SE for joint research within Volodymyrets amber-bearing deposit (a village of Bereznytsia)

Control technology for future aircraft propulsion systems

The need for a more sophisticated engine control system is discussed. The improvements in better thrust-to-weight ratios demand the manipulation of more control inputs. New technological solutions to the engine control problem are practiced. The digital electronic engine control (DEEC) system is a step in the evolution to digital electronic engine control. Technology issues are addressed to ensure a growth in confidence in sophisticated electronic controls for aircraft turbine engines. The need of a control system architecture which permits propulsion controls to be functionally integrated with other aircraft systems is established. Areas of technology studied include: (1) control design methodology; (2) improved modeling and simulation methods; and (3) implementation technologies. Objectives, results and future thrusts are summarized

Effect of sedimentary heterogeneities in the sealing formation on predictive analysis of geological CO₂ storage

Numerical models of geologic carbon sequestration (GCS) in saline aquifers use multiphase fluid flow-characteristic curves (relative permeability and capillary pressure) to represent the interactions of the non-wetting CO2 and the wetting brine. Relative permeability data for many sedimentary formations is very scarce, resulting in the utilisation of mathematical correlations to generate the fluid flow characteristics in these formations. The flow models are essential for the prediction of CO2 storage capacity and trapping mechanisms in the geological media. The observation of pressure dissipation across the storage and sealing formations is relevant for storage capacity and geomechanical analysis during CO2 injection. This paper evaluates the relevance of representing relative permeability variations in the sealing formation when modelling geological CO2 sequestration processes. Here we concentrate on gradational changes in the lower part of the caprock, particularly how they affect pressure evolution within the entire sealing formation when duly represented by relative permeability functions. The results demonstrate the importance of accounting for pore size variations in the mathematical model adopted to generate the characteristic curves for GCS analysis. Gradational changes at the base of the caprock influence the magnitude of pressure that propagates vertically into the caprock from the aquifer, especially at the critical zone (i.e. the region overlying the CO2 plume accumulating at the reservoir-seal interface). A higher degree of overpressure and CO2 storage capacity was observed at the base of caprocks that showed gradation. These results illustrate the need to obtain reliable relative permeability functions for GCS, beyond just permeability and porosity data. The study provides a formative principle for geomechanical simulations that study the possibility of pressure-induced caprock failure during CO2 sequestration

Baseline automotive gas turbine engine development program

Tests results on a baseline engine are presented to document the automotive gas turbine state-of-the-art at the start of the program. The performance characteristics of the engine and of a vehicle powered by this engine are defined. Component improvement concepts in the baseline engine were evaluated on engine dynamometer tests in the complete vehicle on a chassis dynamometer and on road tests. The concepts included advanced combustors, ceramic regenerators, an integrated control system, low cost turbine material, a continuously variable transmission, power-turbine-driven accessories, power augmentation, and linerless insulation in the engine housing

A time-dependent anisotropic model for argillaceous rocks: application to an underground excavation in Callovo-Oxfordian claystone

The paper presents a constitutive model for argillaceous rocks, developed within the framework of elastoplasticity, that includes a number of features that are relevant for a satisfactory description of their hydromechanical behaviour: anisotropy of strength and stiffness, behaviour nonlinearity and occurrence of plastic strains prior to peak strength, significant softening after peak, time-dependent creep deformations and permeability increase due to damage. Both saturated and unsaturated conditions are envisaged. The constitutive model is then applied to the simulation of triaxial and creep tests on Callovo-Oxfordian (COx) claystone. Although the main objective has been the simulation of the COx claystone behaviour, the model can be readily used for other argillaceous materials. The constitutive model developed is then applied, via a suitable coupled hydromechanical formulation, to the analysis of the excavation of a drift in the Meuse/Haute-Marne Underground Research Laboratory. The pattern of observed pore water pressures and displacements, as well as the shape and extent of the damaged zone, are generally satisfactorily reproduced. The relevance and importance of rock anisotropy and of the development of a damaged zone around the excavations are clearly demonstrated.Peer ReviewedPostprint (author's final draft