Sökning: "Fluid computations"

Visar resultat 1 - 5 av 19 uppsatser innehållade orden Fluid computations.

  1. 1. Moderling Acoustic Transmission in Towed Array Sonars : Computations of the coupled acoustic and elastic wave equations

    Master-uppsats, KTH/Matematik (Avd.)

    Författare :Bill Claesson; [2023]
    Nyckelord :;

    Sammanfattning : This thesis presents a method of solving the Helmholtz equation coupled with the Navier-Cauchy equation over a cross section of a Towed Array Sonar (TAS) modeled as a simplified cylindrical shell. The purpose of solving these equations is to estimate the transfer function of the pressure between the outside boundary and a position inside the TAS. LÄS MER

  3. 2. Numerical analysis of aerodynamic damping in a transonic compressor

    Master-uppsats, KTH/Skolan för industriell teknik och management (ITM)

    Författare :Vincenzo Stasolla; [2019]
    Nyckelord :transonic compressor; flutter; vibration; CFD; transonic kompressor; fladder; vibration; CFD;

    Sammanfattning : Aeromechanics is one of the main limitations for more efficient, lighter, cheaper and reliable turbomachines, such as steam or gas turbines, as well as compressors and fans. In fact, aircraft engines designed in the last few years feature more slender, thinner and more highly loaded blades, but this trend gives rise to increased sensitivity for vibrations induced by the fluid and result in increasing challenges regarding structural integrity of the engine. LÄS MER

  4. 3. Supersonic Retro Propulsion Flight Vehicle Engineering of a Human Mission to Mars

    Master-uppsats, Luleå tekniska universitet/Rymdteknik

    Författare :Hanna Marklund; [2019]
    Nyckelord :Supersonic retro propulsion; SRP; Mars; Human mission; Inflatable heat shield;

    Sammanfattning : A manned Mars mission will require a substantial increase in landed mass compared to previous robotic missions, beyond the capabilities of current Entry Descent and Landing, EDL, technologies, such as blunt-body aeroshells and supersonic disk-gap-band parachutes. The heaviest payload successfully landed on Mars to date is the Mars Science Laboratory which delivered the Curiosity rover with an approximate mass of 900 kg. LÄS MER

  5. 4. Efficient seakeeping performance predictions with CFD

    Master-uppsats, KTH/Marina system

    Författare :Benjamin Lagemann; [2019]
    Nyckelord :added wave resistance; CFD; Courant-adapted time step; Euler ˛flow; FINE Marine; inviscid flow; k-ω SST-Menter; KVLCC2; RANS; regular waves; seakeeping; sub-cycling acceleration; time discretization; viscous flow;

    Sammanfattning : With steadily increasing computational power, computational fluid dynamics (CFD) can be applied to unsteady problems such as seakeeping simulations. Therefore, a good balance between accuracy and computational speed is required. LÄS MER

  7. 5. Flow transition prediction approaches evaluated on a single-aisle type aircraft

    Master-uppsats, KTH/Flygdynamik

    Författare :Ilyès Berhouni; [2019]
    Nyckelord :;

    Sammanfattning : Nowadays, as the demand for fuel efficiency is increasing and the manufacturing techniques improved to allow the design of laminar wings, the laminar concepts are being revived and studied, and seen as one of the most promising techniques to reduce skin friction and hence the overall drag of the airframe. In order to predict the kind of benefits that could be obtained from such concepts, computational fluid dynamics (CFD) computations can now be carried out but it is necessary to be able to predict flow transition from laminar to turbulent around the lifting surfaces of the aircraft, such as the wing and the horizontal tail plane. LÄS MER