Search for dissertations about: "low bypass ratio"

Showing result 1 - 5 of 13 swedish dissertations containing the words low bypass ratio.

  1. 1. Power Extraction in Military Aircraft

    Author : Daniel Rosell; Chalmers University of Technology; []
    Keywords : TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ENGINEERING AND TECHNOLOGY; engine performance; mixed flow; turbofan engine; low bypass ratio; Fighter aircraft performance; power extraction;

    Abstract : Military aircraft require more and more power. Pneumatic and hydraulic systems are being replaced by electrical equipment and new, power consuming equipmentis introduced in the aircraft. Increased power extraction brings new challenges for the aircraft jet engine, both in terms of operability and with regards to engine performance. READ MORE

  2. 2. Cerebral Perfusion during Cardiopulmonary Bypass

    Author : Thomas Tovedal; Fredrik Lennmyr; Stefan Thelin; Uppsala universitet; []

    Abstract : Impaired superior vena cava (SVC) cannula outflow during cardiopulmonary bypass (CPB) is a frequent issue, often manifested by only marginal changes in routine monitoring parameters. Nevertheless, significant impact on cerebral perfusion may result. READ MORE

  3. 3. Waiting time and mortality in coronary artery bypass grafting patients

    Author : Helena Rexius; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
    Keywords : coronary artery bypass grafting; waiting time; mortality; gender; risk score;

    Abstract : Coronary Artery Bypass Grafting (CABG) has emerged as one of the most common major surgical procedures worldwide. Unfortunately the capacity is still unable to meet the demand in many countries. This leads to waiting times before surgery, prioritisation between patients and ultimately to deaths among the patients on the waiting list.Aims: 1. READ MORE

  4. 4. Aerodynamic Design and Experimental Investigation of Short Nacelles for Future Turbofan Engines

    Author : Vinícius Tavares Silva; Chalmers University of Technology; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ultra-high-bypass turbofan; Computational Fluid Dynamics; powered nacelle.; Ultra-short nacelles; experimental; thrust-and-drag bookkeeping;

    Abstract : To achieve a higher propulsive efficiency, and hence reduced fuel burn and emissions, the next generation turbofan engines are expected to have higher bypass ratios and lower fan pressure ratios. However, the larger the bypass ratio, the larger becomes the fan and thus the nacelle. The result is an undesired increase in weight and nacelle drag. READ MORE

  5. 5. Optimization and Model Validation of Transonic Compressors

    Author : Lars R Ellbrant; Chalmers University of Technology; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; compressor; optimization; design; metamodels; CFD; validation; multiobjective;

    Abstract : Economical aspects such as reduced specific fuel consumptions and ever growing environmental requirements on emissions and percieved noise levels, are the major drivers in the search for improvement of aircraft engines. For turbofan engines, the global trend is towards higher efficiency which is accomplished by increasing component efficiencies, the bypass ratio and overall pressure ratio while keeping the engine weight low. READ MORE