Sökning: "Aircraft"

Visar resultat 11 - 15 av 375 avhandlingar innehållade ordet Aircraft.

  1. 11. Quasi-analytical Modelling and Optimisation Techniques for Transport Aircraft Design

    Författare :Askin T. Isikveren; KTH; []
    Nyckelord :aircraft; conceptual; design; specifications; atmosphere; geometry; weight; aerodyanmics; propulsion; operational performance; stability and control; constrained multi-objective optimisation; computer aided design; regional; business; high-transonic; ;

    Sammanfattning : The research work presented here focuses on the subject oftransport aircraft design at the pre-design or conceptuallevel. The primary topics addressed are: (1) generation of avast array of new quasi-analytical expressions to permit aconceptual treatment of commercial and business transportaircraft with adequate sensitivity for more advanced tradestudies; (2) review and adoption of a method to predictstability and control characteristics (using the Mitchellmethod); (3) a study of the relative merits between variousmethods in facilitating an expedient and robust constrainedmulti-objective optimisation result within the context oftraditional conceptual design problems (Genetic Algorithms andNelder-Mead Simplex search); (4) creation of a software packageas a new and unique conceptual tool that permits the generationof design proposals in an accurate yet expeditious manner; and,(5) practical demonstration of the new conceptual designsoftware package by undertaking some actual aircraft designproposals. LÄS MER

  3. 12. Acoustical Characteristics of Aircraft Panels

    Författare :Bilong Liu; Leping Feng; Jie Pan; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Acoustics; sound transmission loss; stiffener; stiffening; aircraft panel; cylindrical shell; turbulent boundary layer; TBL; noise; sound radiation; Acoustics; Akustik;

    Sammanfattning : A deterministic approach based on a modal expansion and modal receptance method has been developed to evaluate the airborne sound insulation of aircraft panels with stringer and ring frame attachments. Furthermore, this method was extended to predict the noise radiation of stiffening panel subjected to TBL excitation. LÄS MER

  4. 13. Cost Optimization of Aircraft Structures

    Författare :Markus Kaufmann; Dan Zenkert; Malin Åkermo; Per Wennhage; Erik Lund; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; aircraft structures; optimization; cost estimation; manufacturing cost; direct operating cost; multiobjective optimization; multidisciplinary optimization; composites; airframe design; Vehicle engineering; Farkostteknik;

    Sammanfattning : Composite structures can lower the weight of an airliner significantly. Due to the higher process complexity and the high material cost, however, the low weight often comes with a significant increase in production cost. The application of cost-effective design strategies is one mean to meet this challenge. LÄS MER

  5. 14. Sound transmission through aircraft panels

    Författare :Biong Liu; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; sound transmission loss; stiffener; stiffening; aircraft panel; cylindrical shell; Vehicle engineering; Farkostteknik;

    Sammanfattning : .... LÄS MER

  7. 15. Advances in vortical flow prediction methods for design of delta-winged aircraft

    Författare :Simone Crippa; Arthur Rizzi; James Luckring; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; delta wing; slender wing; aircraft; vortex; VFE-2; CAWAPI; HISAC; Vehicle engineering; Farkostteknik;

    Sammanfattning : This thesis covers the field of vortex-flow dominated external aerodynamics. As part of the contribution to the AVT-113 task group it was possible to prove the feasibility of high Reynolds number CFD computations to resolve and thus better understand the peculiar dual vortex system encountered on the VFE-2 blunt leading edge delta wing at low to moderate incidences. LÄS MER