Search for dissertations about: "Transonic Turbines"

Showing result 1 - 5 of 7 swedish dissertations containing the words Transonic Turbines.

2. 1. Numerical Investigation of Aerodynamic Blade Excitation Mechanisms in Transonic Turbine Stages

   Author : Björn Laumert; KTH; []
   Keywords : Transonic Turbines; CFD; Forced Response; Unsteady Aerodynamics;

   Abstract : With the present drive in turbomachine engine developmenttowards thinner and lighter bladings, closer spaced blade rowsand higher aerodynamic loads per blade row and blade, advanceddesign criteria and accurate prediction methods for vibrationalproblems such as forced response become increasingly importantin order to be able to address and avoid fatigue failures ofthe machine early in the design process. The present worksupports both the search for applicable design criteria and thedevelopment of advanced prediction methods for forced responsein transonic turbine stages. READ MORE

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

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

   Abstract : 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. READ MORE

5. 3. Numerical Methods for Turbomachinery Aeromechanical Predictions

   Author : Maria Angelica Mayorca; Damian Vogt; Torsten Fransson; Robert Kielb; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Aeromechanics; numerical tools; methods; turbomachinery; aeroelasticity; gas turbines; vibrations;

   Abstract : In both aviation and power generation, gas turbines are used as key components. An important driver of technological advance in gas turbines is the race towards environmentally friendly machines, decreasing the fuel burn, community noise and NOx emissions. READ MORE

6. 4. Numerical investigation of the sensitivity of forced response characteristics of bladed disks to mistuning

   Author : Mikkel Myhre; KTH; []
   Keywords : aircraft engines; gas turbines; bladed disk assemblies; vibrations; high cycle fatigue; forced response; mistuning;

   Abstract : Two state of the art finite element reduction techniquespreviously validated against the direct finite element method,one based on classical modal analysis and another based oncomponent mode synthesis, are applied for efficient mistunedfree vibration and forced response analysis of several bladeddisk geometries. The methods are first applied to two testcases in order to demonstrate the differences in computationalefficiency as well as to validate the methods againstexperimental data. READ MORE

7. 5. Aerodynamic Investigation of Leading Edge Contouring and External Cooling on a Transonic Turbine Vane

   Author : Ranjan Saha; Torsten Fransson; Jens Fridh; Tony Arts; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; gas turbine; aerodynamics; secondary flow; external cooling; trailing edge cooling; film cooling; aerodynamic loss; high pressure turbine; nozzle guide vane; Aerospace Engineering; Flyg- och rymdteknik; Energiteknik; Energy Technology;

   Abstract : Efficiency improvement in turbomachines is an important aspect in reducing the use of fossil-based fuel and thereby reducing carbon dioxide emissions in order to achieve a sustainable future. Gas turbines are mainly fossil-based turbomachines powering aviation and land-based power plants. READ MORE