Sökning: "variable cycle engine"

Visar resultat 1 - 5 av 22 avhandlingar innehållade orden variable cycle engine.

1. 1. Development of Methods for Analysis and Optimization of Complex Jet Engine Systems

   Författare :Tomas Grönstedt; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; optimal control; variable cycle engine; performance analysis; double bypass variable cycle engine; jet engine; BDF methods; selective bleed variable cycle engine; turbofan; ODAE;

   Sammanfattning : This thesis describes the development of GESTPAN (GEneral Stationary and Transient Propulsion ANalysis), a generalized system for the design, steady-state and transient simulation of gas turbine systems. Some of the main achievements in the thesis are related to the development of new algorithms or integration of existing numerics tailored to simplify the structure and use of generalized gas turbine simulation systems. LÄS MER

3. 2. Analysis and Evaluation of Innovative Aero Engine Core Concepts

   Författare :Lei Xu; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; intercooled recuperated cycle; intercooler; intercooled cycle; multidisciplinary optimization; turbofan; innovative core; variable core cycle; thermal efficiency; aero engine;

   Sammanfattning : Turbofan engines, which power the majority of the modern aircraft today, have achieved such a high maturity that small improvements of the engine performance requires a large investment. More innovative technologies, including those related to the engine cores, become increasinglyattractive due to the high fuel price in recent years as well as the strict regulations on emissions. LÄS MER

4. 3. On the Analysis of Energy Efficient Aircraft Engines

   Författare :Oskar Thulin; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Performance modelling; Aero engine; Turbofan; Aircraft engine; Installed propulsion; Ultra high bypass ratio; Exergy analysis; Engine weight estimate; Variable area fan nozzle; Multiple pivoting flaps; Translating cowls;

   Sammanfattning : Aero engine performance analysis is highly multidimensional using various measures of component performance such as turbomachinery and mechanical efficiencies, and pressure loss coefficients. Using conventional performance analysis, relying on only the laws of thermodynamics, it is possible to understand how the performance parameters affect the component performance, but it is difficult to directly compare the magnitude of various loss sources. LÄS MER

5. 4. On the Design of Energy Efficient Aero Engines: Some Recent Innovations

   Författare :Rickard Avellan; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; turbofan; aero engine; inter-turbine reheat; emissions; variable cycle; energy efficiency; propeller; NOx; MDO;

   Sammanfattning : In the light of the energy crisis of the 1970s, the old aerospace paradigm of flying higher and faster shifted towards the development of more energy efficient air transport solutions. Today, the aeronautical research and development community is more prone to search for innovative solutions, in particular since the improvement rate of change is decelerating somewhat in terms of energy efficiency, which still is far from any physical limits of aero engine and aircraft design. LÄS MER

7. 5. Estimation of the In-Cylinder Air/Fuel Ratio of an Internal Combustion Engine by the Use of Pressure Sensors

   Författare :Per Tunestål; Förbränningsmotorer; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; vakuumteknik; hydraulik; Maskinteknik; nonlinear; cylinder pressure; engine; least-squares; Mechanical engineering; estimation; hydraulics; vibration and acoustic engineering; vacuum technology; vibrationer; akustik; Motors and propulsion systems; Motorer; framdrivningssystem;

   Sammanfattning : This thesis investigates the use of cylinder pressure measurements for estimation of the in-cylinder air/fuel ratio in a spark ignited internal combustion engine. An estimation model which uses the net heat release profile for estimating the cylinder air/fuel ratio of a spark ignition engine is developed. LÄS MER