Search for dissertations about: "duct flow"

Showing result 16 - 20 of 90 swedish dissertations containing the words duct flow.

  2. 16. Acoustic characterization of orifices and perforated liners with flow and high-level acoustic excitation

    Author : Lin Zhou; Hans Bodén; Wim De Roeck; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Bias Flow; Grazing Flow; Nonlinear Acoustics; Acoustic Impedance; Impedance Eduction; Single Mode Straightforward Method; Uncertainty Analysis; LEE; LNSE; Järnvägsgruppen - Ljud och vibrationer; Järnvägsgruppen - Ljud och vibrationer;

    Abstract : This thesis is motivated by the need for noise control in aircraft engine with orifices and perforated liner. The presence of high-level acoustic excitation, different flow situations either bias flow, grazing flow or any combination in the aircraft engine, makes the acoustic behavior complex due to the interaction between sound and flow over the lined wall. READ MORE

  4. 17. Computational Analysis of Heat Transfer and Fluid Flow with Relevance for IC-Engine Cooling

    Author : Sassan Etemad; Värmeöverföring; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Termisk teknik; termodynamik; turbulence models; Heat transfer; curved duct; secondary flow; IC-engine cooling; Gases; Thermal engineering; applied thermodynamics; Teknik; Technological sciences; plasma; Gaser; fluiddynamik; plasmas; fluid dynamics;

    Abstract : Modern IC-engines produce more power per displaced volume and operate at higher combustion pressures and temperatures. In addition, engine structure materials such as aluminium and magnesium alloys, which are more sensitive to thermal loads, are more commonly used. READ MORE

  5. 18. Experimental Investigation of the Acoustic Properties of Perforate using Acoustic Three-Ports

    Author : Shail A. Shah; Susann Boij; Hans Bodén; Wim De Roeck; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Duct Acoustics; Acoustical Three-port; Perforated plate; Transfer Impedance; Scattering Matrix; Grazing Flow; High-level Excitation; Non-linear effects; Flow-Acoustic Interaction; Rectangular T-Junction; Farkostteknik; Vehicle and Maritime Engineering;

    Abstract : This thesis discusses the aero-acoustic characterisation of a perforate sample using a three-port technique. A rectangular T-junction with a flush mounted perforated sample at the intersection form the acoustical three-port. READ MORE

  6. 19. Flow Control and Shape Optimization of Intermediate Turbine Ducts for Turbofan Engines

    Author : Fredrik Wallin; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; CFD; response surface methodology; intermediate turbine duct; vortex generators; turbine intermediate case; endwall contouring; turbine center frame; body-force model; shape optimization; mid-turbine frame; flow control;

    Abstract : Demands on improved efficiency, reduced emissions and lowered noise levels cause a strive towards high by-pass ratios of commercial turbofan engines. This results in an increased radial offset between the high- and low-pressure turbines. Thus the design of the intermediate turbine duct connecting the two turbines becomes more challenging. READ MORE

  7. 20. Predicting flow-generated noise from HVAC components

    Author : Oscar Kårekull; Mats Åbom; Gunilla Efraimsson; Joachim Golliard; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flow noise; noise prediction; HVAC; flödesalstrat ljud; bullerprediktion; HVAC;

    Abstract : More energy efficient fans, i.e. larger sizes running at lower speeds, in Heating Ventilation and Air Conditioning (HVAC) systems decrease the fan noise and increase the importance of flow generated noise in other system components, e.g. READ MORE