Sökning: "flow propagation velocity"

Visar resultat 1 - 5 av 32 avhandlingar innehållade orden flow propagation velocity.

1. 1. Echocardiography/Doppler for the evaluation of coronary artery function, left ventricular function and the relationship between early diastolic and systolic function

   Författare :Reidar Winter; Malmö Institutionen för kliniska vetenskaper; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; coronary flow reserve; contrast echocardiography; early diastolic downward velocity; flow propagation velocity; colour M-mode; diastolic function; Echocardiography; Doppler; Kardiovaskulära systemet; Cardiovascular system;

   Sammanfattning : Two specific areas of development in echocardiography are assessment of left ventricular (LV) diastolic function and myocardial ischemia. This thesis describes echocardiographic methodology in these two areas. LÄS MER

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

   Författare :Lin Zhou; Hans Bodén; Wim De Roeck; KTH; []
   Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; 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;

   Sammanfattning : 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. LÄS MER

4. 3. Experimental Investigation of Velocity Gust in High Pressure Turbines

   Författare :Kai Freudenreich; KTH; []
   Nyckelord :turbomachinery; unsteady aerodynamics; gust; forcing function; forced response; transonic flow; annular cascade; Laser-Two-Focus Anemometer; experiments;

   Sammanfattning : This thesis investigates the unsteady three-dimensional gustfield in high subsonic and transonic turbine stages based onexperimental velocity data. The generation, propagation andinteraction mechanisms of the velocity gust in high pressureturbines are studied. LÄS MER

5. 4. Vane applications and vane induced flow

   Författare :Fredrick Marelius; KTH; []
   Nyckelord :vane; erosion; shore protection; vortex; scour; ;

   Sammanfattning : Vanes are essentially small aspect ratio foils used forguiding sediment, by means of affecting the flow features. Theyare usually placed on the river bed and aligned with an angleof attack to the approach flow, thereby inducing a secondaryflow component that is used for guiding sediment in a desireddirection. LÄS MER

7. 5. Multiscale Methods for Wave Propagation Problems

   Författare :Henrik Holst; Björn Engquist; Olof Runborg; Assyr Abdulle; KTH; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Simulations of wave propagation in heterogeneous media and at high frequencies are important in many applications such as seismic-, {electro-magnetic-,} acoustic-, fluid flow problems and others. These are classical multiscale problems and often too computationally expensive for direct numerical simulation. LÄS MER