... 2011 21 07 2011 blades cooling flow visualisation mass transfer rotors stators turbulence vortices The efficiency of a gas turbine increases with the temperature of the hot combustion gases at the stage inlet. Modern gas turbines are designed to operate at turbine inlet...

... is generated at the suction side of the blade tip, and then they wrap around each other and roll up into the TLV. We also find that the leakage vortex induces flow separation at the casing endwall and entrains the casing boundary layer with its counter-rotating vorticity. As it propagates in the rotor passage...

... in the stability of the image position. Furthermore, general enhancements of the operability of the PIV system were achieved. The presented investigations of the secondary flow were conducted in stationary and, with the new sequencer technique applied, in rotating mode. Especially in the bend region, vortices...

... meshes generated with POINTWISE . Flow field measurements were independently performed at German Aerospace Centre Cologne using particle image velocimetry. In the smooth channel, rotation had a large impact on secondary flows. Especially, rotation induced vortices completely changed the flow field...

... of the effect of the waist-shaped slot hole’s structure. The middle constriction structure of the waist-shaped slot hole and the coupled vortices makes jets from the waist-shaped slot holes produce higher cooling effectiveness in the midspan region between adjacent holes. And also due to the effect...

... Investigations of the 2D-duct without VGs reveal a large separation. Its onset is displayed by the red rectangle in Fig. 8 . Further downstream two symmetrical counter-rotating vortical structures are visible. The dark green arrows show their direction of rotation. These structures arise from the influence...

... and 800,000. In order to reduce the flow separation and the aerodynamic losses, air jet vortex generators are used, which create streamwise vortices prior to the separation start. Since in high pressure turbine blades film cooling is widely used, also the influence of film cooling both with and without using...

... the Q-criterion, which is used to illustrate vortices ( 32 ), colored by axial velocity, V x , at different times in the cycle. At the beginning of the blowing, there is no separation bubble present near the trailing edge of the airfoil. This is in contrast with the corresponding low T I...

.... The unsteady results compare well with experiment especially for the profile of efficiency difference between close and far. An analysis of results helps to explain the unusual profile seen experimentally that is due to the radial migration of wake generator shed vortices with negative radial velocities near...

... simulations are required to analyze the complex blade and endwall boundary layer interaction. 05 08 2009 03 09 2009 27 10 2010 27 10 2010 aerodynamics blades compressors flow simulation Navier-Stokes equations transonic flow vortices wind tunnels An improvement...

... 2009 27 10 2010 27 10 2010 aerodynamics blades compressors vortices Nowadays, the research and development of energy-efficient gas turbines is driven by economic, as well as environmental demands. In this context, the improvement of compressor efficiency has a major impact...

...L. He Existence of large scale unsteady flow structures manifested in contrarotating vortex pairs has been previously identified in rotor disk cavities. The nonaxisymmetric nature with an unknown number of vortices presents a computational challenge, as a full 360 deg circumferential domain...

... performance when the time-dependent circulation of the shed vortices in the wake is phase-locked to the rotor position, as it occurs when there is strong interaction between the rotor static pressure field and the upstream vanes. The rotor work is found to depend on the path of the wake vortices...

... at the blade suction side corner. The jet strength is modulated by the first vane pressure field. The jets introduce circumferential vorticity as they enter the annulus. As the injected fluid is turned around the rotor leading edge, a streamwise vortex component is created. The dominating leakage vortex has...

... 2007 23 12 2009 28 09 2010 28 09 2010 computational fluid dynamics flow simulation pattern formation turbines vortices The effectiveness of contoured endwalls in reducing secondary flows has been widely proven. Harvey et al. ( 4 ) proposed an endwall design that reduces...

...Stephen P. Lynch; Narayan Sundaram; Karen A. Thole; Atul Kohli; Christopher Lehane Complex vortical secondary flows that are present near the endwall of an axial gas turbine blade are responsible for high heat transfer rates and high aerodynamic losses. The application of nonaxisymmetric, three...

... of pressure probe traversing, endwall pressure taps, and oil flow visualization. Experimental results were also used to validate the numerical setup, which provided a detailed computational picture of the flow field throughout the channel. The influence of the pressure contours’ shape on secondary vorticity...

...Manuel A. Burgos; Roque Corral The effect of the finite extent of a linear cascade on the acoustic and vortical modes generated at the cascade exit by a set of moving bars located at the inlet is assessed by means of a numerical study. The sidewall interference is studied for an airfoil, which...

...% (solid endwall) to 2.5%. Energy loss coefficient, secondary vorticity, and outlet angle distributions were computed from five-hole probe measured data. Contoured endwall results, with and without film cooling, were compared with planar endwall data. Endwall contouring was responsible for a significant...

... acoustic noise aeroacoustics aerodynamics aerospace engines aircraft blades brakes drag turbomachinery vortices wind tunnels Airframe noise depends on an aircraft’s aerodynamic configuration, approach speed, and flight path angle. For modern and next-generation, large civil aircraft...