Multidisciplinary Design and Optimizations of Swept and Leaned Transonic Rotor

Razavi, Seyed Reza; Sammak, Shervin; Boroomand, Masoud

doi:10.1115/1.4037456

Cited by 12 publications

(7 citation statements)

References 18 publications

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“…In particular, tighter operating clearances are desirable between rotating blades and the surrounding casing to reduce tip losses [7]. Blade shapes can also be optimized to increase aerodynamic efficiency or pressure ratio, for example, through the application of three-dimensional (3D) tilt angles [8,9]. In a linear context, the consequences of blade design modifications on its dynamics may be easily quantified with a modal analysis and access to its basic properties such as the variation of mass.…”

Section: Introductionmentioning

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

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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.

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Section: Introductionmentioning

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

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“…Ma et al and Liu et al [19,20] showed that large inlet blade lean can inhibit separation flow and improve turbine efficiency using a multi-objective optimization design method. The research by Razavi et al [21] and He et al [22] reported that the In terms of the methods of suppressing the space diffuser corner separation vortex, Goto et al [11,12] mainly adopted the inverse design method to design two types of blades, i.e., shroud back-loaded and hub forward-loaded blades, for suppressing the corner separation vortexes, the flow was assumed to be irrotational and away from the actual flow conditions. Zhao et al [13] and Zhang et al [14] mainly adopted the method of combining simulation calculation and experiments to analyze the influence of different wrap angles and the number of blades on pump performances when the wrap angle difference is zero, but the inner flow characteristics in the space diffuser were not clear.…”

Section: Introductionmentioning

confidence: 99%

Investigation on the Impact of Trailing Edge Stacking Styles on Hydraulic Performance in the Multistage Submersible Pump Space Diffuser

Zhang,

Cao,

et al. 2023

Processes

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To investigate the effect of the different wrap angles from the hub to the shroud surface in the space diffuser (i.e., the trailing edge stacking style) on the principle of corner separation vortex flow, a numerical simulation method has been conducted in a multistage submersible pump. Building a linear equation on the profile line of the diffuser trailing edge to optimize the wrap angle on every spanwise from the hub to the shroud, and the mapping response relationship between the wrap angle difference and the hydraulic performance in the space diffuser has been analyzed. Under the variable wrap angle difference (Δϕ=ϕhub−ϕshroud), the secondary flows in different directions, non-uniformity, diffuser efficiency, and pressure recovery are compared. The positive wrap angle difference (i.e., the shroud wrap angle is smaller than the hub one) improves the strength of the secondary flow and partly corner separation vortex in the diffuser, so the hydraulic characteristic of positive cases is better than the negative wrap angle difference. Moreover, in scheme A (in which the hub wrap angle is constant and the shroud wrap angle decreasing), the transversal secondary flow has been weakened, the low-energy fluid located in the corner has been suppressed, the extensional secondary flow has been increased, the diffuser hydraulic performance has been improved, and unidirectionally increases with the wrap angle difference increasing. When the shroud wrap angle is constant, the extensional secondary flow has been enhanced by the increasing hub wrap angle. Meanwhile, the increasing extensional secondary flow has been countered by the deteriorating extensional flow at the diffuser inlet and transversal secondary flow, the diffuser hydraulic performance increases and then decreases as the wrap angle difference increases, with an optimal wrap angle difference is about 20°.

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“…For the negative-bow rotor, with the increase of the negative-bow angle, the peak efficiency and the total pressure ratio shows a trend of first increasing and then decreasing. Razavi et al [12] carried out the three-dimensional optimized design of sweep and bow transonic rotors to achieve maximum stage pressure ratio, efficiency, and operating range. The results show that the optimized three-dimensional blade can increase the working range by 30%, the pressure ratio by 1%, and the efficiency by 2%.…”

Section: Introductionmentioning

confidence: 99%

Aerodynamic Study on the Influence Mechanism of Bow Blades on the Flow Field of Supersonic Tandem Rotors

Cheng

Song²,

Liu³

2022

Energies

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In order to research the influence mechanism of bow blades on the flow field of supersonic tandem rotors of compressors, the supersonic rotor rotor37 is taken as the prototype and redesigned as a supersonic tandem rotor. Compared with the prototype rotor37, the efficiency of the design tandem rotor is increased by 0.24% and the stall margin is increased by about 5.6%. Although the negative bow blade deteriorates the flow field in the tip region and the hub region, it significantly increases the efficiency and total pressure ratio of the tandem rotor from 20% span to 85% span. The efficiency of the design point of the tandem rotor with a negative bow angle of 10° is improved by 0.37%, and the stall margin is also increased to 20.71%. Positive bow blades improve the efficiency of the hub region and casing region of tandem rotors, but they significantly reduce the efficiency of the tandem rotor from 10% to 50%. The positive bow blade reduces the pressure ratio and efficiency at the design point and reduces the stall margin of the tandem rotor. The design point efficiency of the tandem rotor with a positive bow angle of 10° is decreased by 0.3%, the stall margin is decreased by 1%, and the mass flow of the design point is increased by 0.38%.

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Multidisciplinary Design and Optimizations of Swept and Leaned Transonic Rotor

Cited by 12 publications

References 18 publications

Blackbox Optimization for Aircraft Engine Blades With Contact Interfaces

Blackbox Optimization for Aircraft Engine Blades With Contact Interfaces

Investigation on the Impact of Trailing Edge Stacking Styles on Hydraulic Performance in the Multistage Submersible Pump Space Diffuser

Aerodynamic Study on the Influence Mechanism of Bow Blades on the Flow Field of Supersonic Tandem Rotors

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