Sökning: "Tip clearance flow"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden Tip clearance flow.

1. 1. Simulation and Optimization of an Axial Compressor Considering Tip Clearance Flow

   Författare :Marcus Lejon; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; design; compressor; optimization; validation; CFD; turbulence models; tip clearance;

   Sammanfattning : With ever-increasing demands for high efficiency in axial compressors, it has become important to consider more geometrical features of the manufactured component in the design phase. Many possibilities open if the level of fidelity of the computational model can be increased. LÄS MER

3. 2. Improved Flutter Prediction for Turbomachinery Blades with Tip Clearance Flows

   Författare :Tianrui Sun; Andrew R. Martin; Paul Petrie-Repar; Mihai Mihaescu; KTH; []
   Nyckelord :Steam turbine; Flutter; Aeroelastic stability; Tip clearance flow; Detached-Eddy Simulation; Energiteknik; Energy Technology;

   Sammanfattning : Recent design trends in steam turbines strive for high aerodynamic loading and high aspect ratio to meet the demand of higher efficiency. These design trends together with the low structural frequency in last stage steam turbines increase the susceptibility of the turbine blades to flutter. LÄS MER

4. 3. Numerical Simulation of Some Heat Transfer and Fluid Flow Phenomena for Gas Turbine Blades and a Transonic Turbine Stage

   Författare :Fadil Mumic; Värmeöverföring; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fluiddynamik; plasma; Thermal engineering; applied thermodynamics; plasmas; Gaser; fluid dynamics; Gases; transonic; numerical; heat transfer coefficient; shroud surface; squealer blade tip; flat blade tip; leakage flow; Termisk teknik; termodynamik; turbulence modeling;

   Sammanfattning : With the attempts to achieve higher thermal efficiency, turbine blades are exposed to very high temperature gases and may undergo severe thermal stress and fatigue. Thus, in order to develop optimal cooling strategies and reduce the heat transfer it is important to obtain a good understanding of both the complex flow field and the heat transfer characteristics in turbine rotor/stator hot-gas passages. LÄS MER

5. 4. Numerical Prediction of Propeller Induced Hull Pressure Pulses

   Författare :Muye Ge; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cavitation; Pressure pulses; RANS; OpenFOAM; Star-CCM ;

   Sammanfattning : Ship propeller induced pressure pulses is one of the major sources of both onboard noise and vibration as well as underwater radiated noise. The need for accurate pressure pulse prediction is increasing due to rising concerns of environmental impacts and comfort and welfare of passengers and crews. LÄS MER

7. 5. Experimental Investigation of Three-Dimensional Mechanisms in Low-Pressure Turbine Flutter

   Författare :Damian Vogt; Torsten Fransson; Robert Kielb; KTH; []
   Nyckelord :Life sciences and physical sciences; turbomachinery; flutter; aeroelastic instability; aeroelastic testing; CFD; linearized unsteady numerical method; 3D aerodynamic effects; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP;

   Sammanfattning : The continuous trend in gas turbine design towards lighter, more powerful and more reliable engines on one side and use of alternative fuels on the other side renders flutter problems as one of the paramount challenges in engine design. Flutter denotes a self-excited and self-sustained aeroelastic instability phenomenon that can lead to material fatigue and eventually damage of structure in a short period of time unless properly damped. LÄS MER