A study on an axial-type 2-D turbine blade shape for reducing the blade profile loss

Cho, Soo-Yong; Yoon, Eul Sik; Choi, Bum-Seog

doi:10.1007/bf02984026

Cited by 12 publications

(12 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The proposed modeling of blade profiles, depicted in Fig. 5, builds on the work of Pritchard [19] and Cho [20]. The model relies on the use of two elliptical arcs for the leading edge, one circular arc for the trailing edge, and two spline curves for the representation of both the suction side and the pressure side.…”

Section: Definitionmentioning

confidence: 99%

Blackbox Optimization for Aircraft Engine Blades With Contact Interfaces

Lainé

Piollet

Nyssen

et al. 2019

Journal of Engineering for Gas Turbines and Power

View full text Add to dashboard Cite

In modern aircraft engines, reduced operating clearances between rotating blade tips and the surrounding casing increase the risk of blade/casing structural contacts, which may lead to high blade vibration levels. Therefore, structural contacts must now be accounted for as early as in the engine design stage. As the vibrations resulting from contact are intrinsically nonlinear, direct optimization of blade shapes based on vibration simulation is not realistic in an industrial context. A recent study on a blade featuring significantly lower vibration levels following contact event identified a potential criterion to estimate a blade sensitivity to contact interactions. This criterion is based on the notion of dynamic clearance, a quantity describing the evolution of the blade/casing clearance as the blade vibrates along one of its free-vibration modes. This paper presents an optimization procedure, which minimizes the dynamic clearance as a first step toward the integration of structural criteria in blade design. A dedicated blade geometry parameterization is introduced to allow for an efficient optimization of the blade shape. The optimization procedure is applied to the three-dimensional (3D) properties of two different blades. In both cases, initial and optimized blades are compared by means of an in-house numerical tool dedicated to the simulation of structural contact events with a surrounding casing. The simulations focus on rubbing phenomena, involving the vibration of a single blade. Simulation results show a significant reduction of vibration levels following contact interactions for the optimized blades. Critical speeds related to the mode on which the dynamic clearance is computed are successfully eliminated by the blade shape optimization. For the investigated blade geometries, backward sweep and backward lean angles are associated with reduced contact interactions compared to forward sweep and forward lean angles.

show abstract

Section: Definitionmentioning

confidence: 99%

Blackbox Optimization for Aircraft Engine Blades With Contact Interfaces

Lainé

Piollet

Nyssen

et al. 2019

Journal of Engineering for Gas Turbines and Power

View full text Add to dashboard Cite

show abstract

“…The proposed modeling of blade profiles, depicted in Fig. 2, builds on the work of Pritchard [18] and Cho [19]. It relies on the use of two elliptical arcs for the leading edge, one circular arc for the trailing edge, and two spline curves for the representation of both the suction side and the pressure side.…”

Section: Parameterizationmentioning

confidence: 99%

“…6, controls the blade tilt with the lean angle (15) and the sweep angle (16) and the blade curvature with the bowed distance (17). The hub radius (18) and the blade height (19) give the radial positions of the root profile and the tip profile.…”

Section: Stacking Linementioning

confidence: 99%

“…19 are directly related to the blade intrinsic vibration behavior. (15) 0 mm 0 mm lean angle (16) 0 mm 0 mm bowed distance (17) 10 mm 8 mm hub radius (18) 350 mm 350 mm blade height (19) 150 mm 150 mm angle of incidence (20) 0 mm 0 mm stagger angle (21) 0 mm 0 mm Table 3. initial and optimized parameters of the investigated blade model From Fig.…”

Section: Optimized Blade Model Analysismentioning

confidence: 99%

See 1 more Smart Citation

Towards the Structural Optimization of Bladed Components Featuring Contact Interfaces

Lainé

Piollet

Batailly

2018

Volume 7A: Structures and Dynamics

View full text Add to dashboard Cite

In order to maximize their efficiency, modern aircraft engines feature reduced nominal clearances between rotating (such as bladed disks) and static (casing) components. As a consequence, structural contacts between these components are now more likely to occur and must be accounted for as early as in the design stage of the engine. To this day, there exists no relevant criterion to discriminate contacting components, such as blades, according to their sensitivity to contact events. In a recent study, it was found that a redesigned blade, featuring significant improvements with respect to its vibratory response following structural contacts, essentially differed from the original design with respect to its clearance consumption — a quantity that characterizes the evolution of blade/casing clearance as the blade vibrates over its first free-vibration modes. From this observation, it was decided to carry out a thorough investigation on the possible relation between clearance consumption and the nonlinear vibratory response following structural contacts. This paper presents an automated structural optimization procedure of a blade design using an objective-function related to the blade’s clearance consumption. Thus, optimized blades feature a lower clearance consumption. By means of an in-house numerical tool dedicated to the simulation of structural contact events with a surrounding casing, it is found that optimized blades feature lower amplitudes of vibration following contacts in comparison with the original blades. Overall, it is evidenced that the blade sensitivity to contact has been lowered as certain critical speeds vanish for the optimized profile. The current paper aims at establishing a proof-of-concept and thus only considers structural aspects. Aerodynamic considerations that are key for designing efficient blades are purposely left aside in order to focus on the feasibility of blade dynamics optimization.

show abstract

“…Today, computational fluid dynamics (CFD) techniques are widely used to capture more detailed flow physics and design more efficient gas turbine engine components [4][5][6][7]. However, in flow fields sensitive to turbulence properties such as film cooling or heat transfer rates [8], CFD provides diverse results depending on the turbulence model used.…”

Section: Introductionmentioning

confidence: 99%

One-pitch passage designed inversely with a single blade for cascade experiments

et al. 2010

Self Cite

View full text Add to dashboard Cite

A linear cascade experimental apparatus often consists of only a few cascade blades. Advantages to this experimental arrangement are increased by the use of larger cascade blades, a lower mass flow rate, a corresponding decrease in required power, and easier optical access within the cascade passage. However, fewer cascade blades in the cascade row make it difficult to establish periodic flow conditions between blades compared to infinite cascade model experiments. Generally, removing fluid from the cascade walls or adjusting tailboards located downstream of the cascade are common methods to establish periodic flow conditions through the cascade blades. In this study, a passage for cascade experiments is designed to satisfy infinite cascade flow conditions without any flow control or tailboards. A one-pitch at cascade row is adopted as its width and only a single cascade blade is installed within the passage. The surface isentropic Mach number distribution on the blade is chosen for the existence of infinite cascade flow conditions, and 14 geometric design variables related to the passage shape are applied to the design of a one-pitch passage by using a genetic algorithm. Flow structures within a passage designed using a genetic algorithm match with those obtained with the infinite cascade flow condition. Computed results obtained with a single cascade blade show that infinite cascade flow conditions can be obtained by modifying only the passage walls of the cascade experimental apparatus.

show abstract

A study on an axial-type 2-D turbine blade shape for reducing the blade profile loss

Cited by 12 publications

References 8 publications

Blackbox Optimization for Aircraft Engine Blades With Contact Interfaces

Blackbox Optimization for Aircraft Engine Blades With Contact Interfaces

Towards the Structural Optimization of Bladed Components Featuring Contact Interfaces

One-pitch passage designed inversely with a single blade for cascade experiments

Contact Info

Product

Resources

About