Leakage Uncertainties in Compressors: The Case of Rotor 37

Seshadri, Pranay; Parks, Geoffrey T.; Shahpar, Shahrokh

doi:10.2514/1.b35039

Cited by 42 publications

(29 citation statements)

References 17 publications

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“…(20). We omit a detailed flow validation here and direct interested readers to Refs (24,29), where experiment vs CFD validations for the PADRAM-HYDRA suite of tools are provided for representative transonic fan blades. Boundary conditions and the inlet Reynolds number for the four design of experiments carried out in this study are given in Table 2.…”

Section: Computational Flow Solver and Constitutive Equationsmentioning

confidence: 99%

Supporting multi-point fan design with dimension reduction

et al. 2020

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Motivated by the idea of turbomachinery active subspace performance maps, this paper studies dimension reduction in turbomachinery 3D CFD simulations. First, we show that these subspaces exist across different blades—under the same parametrisation—largely independent of their Mach number or Reynolds number. This is demonstrated via a numerical study on three different blades. Then, in an attempt to reduce the computational cost of identifying a suitable dimension reducing subspace, we examine statistical sufficient dimension reduction methods, including sliced inverse regression, sliced average variance estimation, principal Hessian directions and contour regression. Unsatisfied by these results, we evaluate a new idea based on polynomial variable projection—a non-linear least-squares problem. Our results using polynomial variable projection clearly demonstrate that one can accurately identify dimension reducing subspaces for turbomachinery functionals at a fraction of the cost associated with prior methods. We apply these subspaces to the problem of comparing design configurations across different flight points on a working line of a fan blade. We demonstrate how designs that offer a healthy compromise between performance at cruise and sea-level conditions can be easily found by visually inspecting their subspaces.

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Section: Computational Flow Solver and Constitutive Equationsmentioning

confidence: 99%

Supporting multi-point fan design with dimension reduction

et al. 2020

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“…The very high pressure ratio, strong shock wave-boundary layer interaction, large tipleakage vortex and highly separated flow mean that it poses challenges for turbomachinery solvers. Rotor 37 has been the subject of review articles that highlight the complexity of matching experimental and computational measurements and the associated uncertainties [19] [20] [21].…”

Section: St Case: Nasa Rotor 37mentioning

confidence: 99%

“…The differences are usually attributed to uncertainty in the experimental measurements, the lack of real geometry in the simulations (e.g. the upstream hub cavity is usually missing) [21] and also the difficulty in fully resolving the complex flows. Figures 6 and 7 show comparisons of the current simulation results versus the experiment.…”

Section: Validationmentioning

confidence: 99%

Using Shock Control Bumps to Improve Transonic Fan/Compressor Blade Performance

John

Qin

Shahpar

2019

Journal of Turbomachinery

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Shock control bumps can help to delay and weaken shocks, reducing loss generation and shock-induced separation and delaying stall inception for transonic turbomachinery components. The use of shock control bumps on turbomachinery blades is investigated here for the first time using 3D analysis. The aerodynamic optimization of a modern research fan blade and a highly loaded compressor blade is carried out using shock control bumps to improve their performance. Both the efficiency and stall margin of transonic fan and compressor blades may be increased through the addition of shock control bumps to the geometry. It is shown how shock-induced separation can be delayed and reduced for both cases. A significant efficiency improvement is shown for the compressor blade across its characteristic, and the stall margin of the fan blade is increased by designing bumps that reduce shock-induced separation near to stall. Adjoint surface sensitivities are used to highlight the critical regions of the blade geometries, and it is shown how adding bumps in these regions improves blade performance. Finally, the performance of the optimized geometries at conditions away from where they are designed is analyzed in detail.

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“…Pranay Seshadri (Seshadri et al, 2014) studied the influence of tip clearance variation in aerodynamic performances and showed that higher efficiency in tip region can produce higher mixed-out losses. Pranay Seshadri (Seshadri et al, 2015) concentrated on the uncertainty of leakage mass flow, leakage whirl velocity, and radial flow angle, and stressed on the influence of leakage flow on the hub pressure deficit at both on-and off-design conditions. Remy Nigro (Nigro et al, 2017) studied correlated uncertainties on the blade geometry of the NASA Rotor 37.…”

Section: Introductionmentioning

confidence: 99%

Uncertainty Analysis of Aerodynamic Performance for Tip Clearance Size of Compressor

Ma¹,

Gao²,

Li³

et al. 2019

Proceedings of Global Power &Amp; Propulsion Society

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Blade tip clearance plays a vital role on aerodynamic performance of compressor. Slightly change of tip clearance size can result in violent change of the tip clearance flow field, and subsequently seriously affect the aerodynamic performances. Since the clearance size is subject to variabilities influenced by working conditions, manufacture, complex service process and some other factors, to improve the aerodynamic performance of tip clearance region, it is essential to study the influence of the tip clearance uncertainty on the flow field and aerodynamic performance parameters. In this paper, the tip clearance size distributions over different rotating speeds are respectively mapped. Generally, the tip clearance sizes for different working conditions satisfy the Gaussian distributions, where the mean value and standard deviation can be changed according to the conditions. Non-Intrusive Polynomial Chaos (NIPC) is introduced here to achieve the uncertainty quantification (UQ) of output aerodynamic performance parameters of compressor. The various impacts of input tip clearance size uncertainty under different working conditions are investigated here, as well as the differences and relations of these impacts on the aerodynamic Quantity of Interest (QoI). With this methodology, it is practicable to analyse the specific effects of stochastic tip clearance on compressor aerodynamic performance for different working conditions. The UQ results show that part rotating speeds conditions are more sensitive to the tip clearance size uncertainty, especially the near stall operating points. The results of this research provide some useful information to improve compressor design process and some meaningful hints for further robust design. The results shown in this paper can serve as study case for further comparisons with other UQ methodology and results as well.

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Leakage Uncertainties in Compressors: The Case of Rotor 37

Cited by 42 publications

References 17 publications

Supporting multi-point fan design with dimension reduction

Supporting multi-point fan design with dimension reduction

Using Shock Control Bumps to Improve Transonic Fan/Compressor Blade Performance

Uncertainty Analysis of Aerodynamic Performance for Tip Clearance Size of Compressor

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