Influence of Stator Clocking on the Unsteady Three-Dimensional Flow in a Two-Stage Turbine

This paper presents the results of stator clocking investigations at a design point and an operating point near the stability limit in a low-speed research compressor (LSRC).The unsteady flow field of the LSRC at several clocking configurations was investigated using a three-dimensional unsteady, viscous solver. The unsteady pressure on the rotor blades at midspan (MS) was measured using time-resolving piezoresistive miniature pressure transducers.The effect of clocking on the unsteady pressure fluctuation at MS on the rotor blades is discussed for different operating points.Based on the unsteady profile pressures, the blade pressure forces were calculated. The peakto-peak amplitudes of the unsteady blade pressure forces are presented and analysed for different clocking positions at both the design point and the operating point near the stability limit of the compressor.

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“…Further investigations on the effect of clocking on the performance were done by Reinmoeller et al [4], Arnone et al [5], and Bohn et al [6].…”

Section: Introductionmentioning

confidence: 99%

Effect of clocking on unsteady rotor blade loading in a low-speed axial compressor at design and off-design operating conditions

Jia

Müller

et al. 2008

Proceedings of the Institution of Mechanical Engineers, Part G:

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“…The author reports the positive effect of the vane-vane interaction on the LP stator performance when the first stator wake avenue impinges on the leading edge of the second stator. Similar conclusions on the potential benefit of clocking were drawn by other researchers in a number of experimental and numerical studies (Reinmöller et al [136], Bohn [137]). Few works have treated specifically the interaction mechanisms between a HP turbine and a second stator positioned in an s-shaped diffuser.…”

Section: Figure 51: Evolution Of the Multi-profile Designsupporting

confidence: 70%

On the Aerothermal Flow Field in a Transonic HP Turbine Stage with a Multi-Profile LP Stator Vane

Lavagnoli¹

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The quest for higher performances and durability of modern aero-engines requires the understanding of the complex aero-thermal flow experienced in a multi-row environment. In particular, the high and low pressure turbine components have a great impact into the engine overall performance, and improvements in the turbine efficiencies can only be achieved through detailed research on the three-dimensional unsteady aerodynamics and heat transfer. The present thesis presents an experimental study of the aerothermodynamics in one and a half turbine stage, focusing on: the aero-thermal flow in the overtip region of a transonic highly loaded high pressure (HP) rotor, and the aerodynamics and heat transfer of an innovative low pressure (LP) stator with a multi-profile configuration placed downstream of the high pressure turbine, within an s-shaped duct.Advanced instrumentation and measurement techniques were used and developed to perform the experimental investigation in a short-duration turbine test rig where both high spatial and time accuracy is indispensable. The flow field at the rotor shroud was investigated with simultaneous measurements of heat transfer, static pressure and blade tip clearance by using fast response pressure, wall temperature and capacitance probes. Through repeat experiments at the same turbine operating point, the time-averaged and time-resolved adiabatic wall temperature and convective heat transfer coefficient were evaluated.In the frame of new engine architectures, a novel stator for a LP turbine is proposed with a multi-splitter layout that represents a new design solution towards compact, lighter and performing aero-engine turbomachinery. It contains small aero-vanes and large structural aerodynamic airfoils which are used to support the engine shaft and house service devices. The research focuses on the experimental investigation of the global performance, aerodynamics and thermodynamics of this novel HP-LP vane layout. The turbine was tested at three operating regimes depending on the pressure ratio and the rotational speed. Time-averaged and time-resolved surface pressure and heat flux measurements at the mid-section of the multi-splitter stator were used to characterize the steady and unsteady aero-thermal flow field. State-of-art CFD simulations were used to support the analysis and the understanding of the complex phenomena that characterize the flow physics and assess the efficiency of the structural LP vane at design and off-design conditions.The goals of the research were to provide guidelines to design future aeroengines and promote the understanding of the flow physics in transonic turbine multi-row environments through analysis of the experimental data and comparison with the numerical models. The study provides an extensive experimental database to improve and validate turbomachinery CFD simulations. vi ResumenEl incremento de la eficiencia y la fiabilidad de los actuales aeromotores requiere comprender el complejo flujo aero-termodinámico en presencia de varias cascad...

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“…Further investigations on the wake were carried out by Korakianitis 11 and Henderson et al 12 It can be seen from these investigations that the IGV or upstream stator wake can produce variations in performance and flow of successive rotor and stator blade row. However, the complexity of the flow phenomena involved makes it difficult to draw general conclusion [13][14][15] which indicate the need of further studies.It is obvious that most of the previous studies were focused on the axial compressors and turbines, but only H. few reports focused on the centrifugal compressors. The IGV wake effect in centrifugal compressor is largely neglected.…”

mentioning

confidence: 99%

mentioning

confidence: 99%

Igv Wake Effect in Centrifugal Compressor

Jiang

Gong

et al. 2010

Experimental Techniques

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Influence of Stator Clocking on the Unsteady Three-Dimensional Flow in a Two-Stage Turbine

Cited by 22 publications

References 12 publications

Effect of clocking on unsteady rotor blade loading in a low-speed axial compressor at design and off-design operating conditions

Effect of clocking on unsteady rotor blade loading in a low-speed axial compressor at design and off-design operating conditions

On the Aerothermal Flow Field in a Transonic HP Turbine Stage with a Multi-Profile LP Stator Vane

Igv Wake Effect in Centrifugal Compressor

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