Sökning: "axial turbine"

Visar resultat 1 - 5 av 40 avhandlingar innehållade orden axial turbine.

1. 1. Engine Optimized Turbine Design

   Författare :Nicholas Anton; Anders Christiansen-Erlandsson; Magnus Genrup; Marc Gugau; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbocharger; Heavy-duty; Turbine; Axial; Radial; Machine Design; Maskinkonstruktion;

   Sammanfattning : The focus on our environment has never been as great as it is today. The impact of global warming and emissions from combustion processes become increasingly more evident with growing concerns among the world’s inhabitants. The consequences of extreme weather events, rising sea levels, urban air quality, etc. LÄS MER

3. 2. Numerical investigation of the flow and instabilities at part-load and speed-no-load in an axial turbine

   Författare :Jelle Kranenbarg; Michel Cervantes; Lisa Prahl Wittberg; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Speed-no-load; vortical flow structures; flow instabilities; rotating stall; mitigation; independent guide vanes; axial turbine; swirling flow; off design operation; URANS; parametric study; blade clearance; head losses; diffusor; GEKO model; flow separation; hydraulic turbine; Strömningslära; Fluid Mechanics;

   Sammanfattning : Global renewable energy requirements rapidly increase with the transition to a fossil-free society. As a result, intermittent energy resources, such as wind- and solar power, have become increasingly popular. However, their energy production varies over time, both in the short- and long term. LÄS MER

4. 3. Experimental Investigation of Performance, Flow Interactions and Rotor Forcing in Axial Partial Admission Turbines

   Författare :Jens Fridh; Torsten Fransson; Björn Laumert; Jürgen Seume; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; axial turbine; partial admission; part loads; experimental investigation; turbine performance; losses; dynamic rotor forces; forced response; unsteady flow; axialturbin; partialpådrag; dellaster; reglersteg; experimentell undersökning; turbinprestanda; förluster; dynamiska krafter; rotorvibration; instationär strömning;

   Sammanfattning : The thesis comprises a collection of four papers with preceding summary and supplementary appendices. The core investigation solely is of experimental nature although reference and comparisons with numerical models will be addressed. LÄS MER

5. 4. Flow Control and Shape Optimization of Intermediate Turbine Ducts for Turbofan Engines

   Författare :Fredrik Wallin; Chalmers tekniska högskola; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

7. 5. Numerical Investigation of the Aerodynamic Vibration Excitation of High-Pressure Turbine Rotors

   Författare :Markus Jöcker; KTH; []
   Nyckelord :Aeroelasticity; Aerodynamics; Stator-Rotor Interaction; Excitation Mechanism; Unsteady Flow Computation; Forced Response; High Cycle Fatigue; Turbomachinery; Gas-Turbine; High-Pressure Turbine; Turbopump; CFD; Design;

   Sammanfattning : The design parameters axial gap and stator count of highpressure turbine stages are evaluated numerically towards theirinfluence on the unsteady aerodynamic excitation of rotorblades. Of particular interest is if and how unsteadyaerodynamic considerations in the design could reduce the riskofhigh cycle fatigue (HCF) failures of the turbine rotor. LÄS MER