scholarly journals Aero-Structural Coupling Strategy for a Morphing Blade Cascade Study

2021 ◽  
pp. 1-31
Author(s):  
Giada Abate ◽  
Johannes Riemenschneider ◽  
Alexander Hergt
Keyword(s):  
Structural Analysis ◽  
Three Dimensional ◽  
Leading Edge ◽  
Structural Coupling ◽  
Aerodynamic Loads ◽  
Pressure Loss Coefficient ◽  
Blade Cascade ◽  
Coupling Loop ◽  
Coupling Strategy ◽  
Airfoil Cascade

Abstract The coupling of aerodynamics and structural mechanics is an important step in the design process of aeronautical devices with morphing parts. In this paper, a 2D-3D coupling approach is developed to study a morphing blade cascade. Two shape memory alloy actuators are placed on the upper and lower sides of the blade to make possible the change in shape of the leading-edge. In the present work, a preliminary design study is conducted by considering a two-dimensional CFD analysis of an airfoil cascade coupled with a three-dimensional structural analysis of the whole 3D blade. A methodology is developed to match 2D and 3D meshes such that the aerodynamic loads can be easily transferred to the structural analysis. From there, the deformed blade geometry due to both aerodynamic loads and actuator work can be transferred back to the CFD solver, and the iterative aero-structural coupling loop can be repeated until convergence. The aero-structural coupling strategy developed in this work is also applied to a blade cascade study aiming to improve its performance by morphing the leading-edge of the blade. The results of this application show that by morphing the leading-edge blade of only few millimeters (less than 2 mm), it is possible to achieve a relevant performance improvement in terms of total pressure loss coefficient decrease of about 53%.

Numerical Investigation of the Three-Dimensional Flow Structure About a Revolving Wing

2012 ◽  
Author(s):  
Daniel J. Garmann ◽  
Miguel R. Visbal ◽  
Paul D. Orkwis
Keyword(s):  
Turbulent Flows ◽  
Numerical Study ◽  
Three Dimensional ◽  
Leading Edge ◽  
Reynolds Numbers ◽  
Vortex System ◽  
Aerodynamic Loads ◽  
Eddy Simulation ◽  
Data Reduction Technique ◽  
The Stability

A numerical study is conducted to examine the vortex structure about a revolving wing in quiescent flow employing a high-fidelity, implicit large eddy simulation (ILES) technique found to be effective in simulating flows that exhibit interspersed regions of laminar, transitional, and turbulent flows. The revolving wing configuration consists of a single, aspect ratio one rectangular plate extended out a distance of 0.5 chords from the origin. Shortly after the onset of the motion, the rotating wing generates a stable and coherent vortex system across the leading edge and wing root that remains throughout the motion. The aerodynamic loads are also analyzed and found to remain mostly constant during the maneuver. Transitional effects on the vortex system are investigated over a range of Reynolds numbers (3,000 < Re < 15,000). It is found that higher Reynolds numbers promote more breakdown of the leading edge and root vortices, but do not alter the stability of the vortex system. The aerodynamic loads also show little sensitivity to Reynolds number with the higher Reynolds numbers producing only moderately higher forces. Comparisons with recent experimental PIV measurements using a PIV-like data reduction technique applied to the computational solution show very favorable agreement with the mid-span velocity and vorticity contours.

Comprehensive Geometric Description of Manufacturing Scatter of High-Pressure Turbine Nozzle Guide Vanes for Probabilistic CFD Analysis

2019 ◽  
Vol 141 (8) ◽  
Author(s):  
Paul Voigt ◽  
Lars Högner ◽  
Barbara Fiedler ◽  
Matthias Voigt ◽  
Ronald Mailach ◽  
...  
Keyword(s):  
High Pressure ◽  
Film Cooling ◽  
Guide Vane ◽  
Input Parameter ◽  
Three Dimensional ◽  
Leading Edge ◽  
Scanning System ◽  
High Pressure Turbine ◽  
Pressure Loss Coefficient ◽  
Nozzle Guide

The increasing demands on jet engines require progressive thermodynamic process parameters, which typically lead to higher aerothermal loadings and accordingly to designs with high complexity. State-of-the-art high-pressure turbine (HPT) nozzle guide vane (NGV) design involves vane profiles with three-dimensional features including a high amount of film cooling and profiled endwalls (PEWs). Typically, the specific mass flow, also called capacity, which governs the engine's operation, is set by the HPT NGV. Hence, geometric variations due to manufacturing scatter of the HPT NGV's passage can affect relevant aerodynamic quantities and the entire engine behavior. Within the traditional deterministic design approach, the influences of those geometric variations are covered by conservative assumptions and engineering experience. This paper addresses the consideration of variability due to the manufacturing of HPT NGVs through probabilistic CFD investigations. To establish a statistical database, 80 HPT NGVs are digitized with a high precision optical 3D scanning system to record the outer geometry. The vane profiles are parametrized by a section-based approach. For this purpose, traditional profile theory is combined with a novel method that enables the description of NGV profile variability taking the particular leading edge (LE) shape into account. Furthermore, the geometric variability of PEWs is incorporated by means of principle component analysis (PCA). On this basis, a probabilistic system assessment including a sensitivity analysis in terms of capacity and total pressure loss coefficient is realized. Sampling-based methods are applied to conduct a variety of 3D CFD simulations for a typical population of profile and endwall geometries. This probabilistic investigation using realistic input parameter distributions and correlations contributes to a robust NGV design in terms of relevant aerodynamic quantities.

Flowfield in a Film-Cooled Three-Dimensional Contoured Endwall Passage: Aerodynamic Measurements

2007 ◽  
Author(s):  
Ross Gustafson ◽  
Gazi I. Mahmood ◽  
Sumanta Acharya
Keyword(s):  
Film Cooling ◽  
Total Pressure ◽  
Three Dimensional ◽  
Leading Edge ◽  
Suction Side ◽  
Axial Direction ◽  
Turbine Rotor ◽  
Suction Surface ◽  
Pressure Loss Coefficient ◽  
Profile Height

The influence of endwall film cooling on the aerodynamic performance of a linear blade cascade employing an asymmetric contoured endwall is measured. Cylindrical coolant holes are strategically located on the contoured endwall to provide full coverage film cooling. The endwall contour is varied along the pitch direction, and is elevated near the pressure side and depressed near the suction surface. The profile height also varies in the axial direction from the inlet to exit. Measurements of total pressure, vorticity, and velocity components are obtained at different axial locations inside the passage for six inlet blowing ratios ranging from 1.0 to 2.4. The results are compared with the measured data on the contoured endwall without any film cooling flow (uncooled case). All the tests are performed in a low speed cascade facility employing a scaled up two-dimensional blade profile of the GE-E3 turbine rotor section. The Reynolds number based on the cascade inlet velocity and blade actual chord is 2.30×105. The results near the leading edge show that the suction side-leg vortex on the uncooled endwall weakens when the film cooling jets are employed. The axial vorticity and velocity vectors near the exit plane indicate that the passage vortex is located nearer to the mid-pitch location and higher above the endwall for the film-cooled endwall than for the uncooled contoured endwall. While the overall total pressure loss coefficient across the passage decreases at the high blowing ratios compared to the uncooled case, the overall cascade loss increases with the blowing ratio.

Comprehensive Geometric Description of Manufacturing Scatter of High Pressure Turbine Nozzle Guide Vanes for Probabilistic CFD Analysis

2018 ◽  
Author(s):  
Paul Voigt ◽  
Lars Högner ◽  
Barbara Fiedler ◽  
Matthias Voigt ◽  
Ronald Mailach ◽  
...  
Keyword(s):  
High Pressure ◽  
Film Cooling ◽  
Guide Vane ◽  
Input Parameter ◽  
Three Dimensional ◽  
Leading Edge ◽  
Scanning System ◽  
High Pressure Turbine ◽  
Pressure Loss Coefficient ◽  
Nozzle Guide

The increasing demands on jet engines require progressive thermodynamic process parameters, which typically lead to higher aerothermal loadings and accordingly to designs with high complexity. State of the art high pressure turbine (HPT) nozzle guide vane (NGV) design involves vane profiles with three-dimensional features including a high amount of film cooling and profiled endwalls (PEW). Typically, the specific massflow, also called capacity, which governs the engine’s operation, is set by the HPT NGV. Hence, geometric variations due to manufacturing scatter of the HPT NGV’s passage can affect relevant aerodynamic quantities and the entire engine behavior. Within the traditional deterministic design approach, the influences of those geometric variations are covered by conservative assumptions and engineering experience. This paper addresses the consideration of variability due to manufacturing of HPT NGVs through probabilistic CFD investigations. In order to establish a statistical database, 80 HPT NGVs are digitized with a high precision optical 3D scanning system to record the outer geometry. The vane profiles are parametrized by a section based approach. For this purpose, traditional profile theory is combined with a novel method that enables the description of NGV profile variability taking the particular leading edge (LE) shape into account. Furthermore, the geometric variability of PEWs is incorporated by means of principle component analysis (PCA). On this basis, a probabilistic system assessment including a sensitivity analysis in terms of capacity and total pressure loss coefficient is realized. Sampling-based methods are applied in order to conduct a variety of 3D CFD simulations for a typical population of profile and endwall geometries. This probabilistic investigation using realistic input parameter distributions and correlations contributes to a robust NGV design in terms of relevant aerodynamic quantities.

Three-dimensional thermal structural analysis of a swept cowl leading edge subjected to skewed shock-shock interference heating

10.2514/3.317 ◽  
1992 ◽  
Vol 6 (1) ◽  
pp. 48-54 ◽  
Author(s):  
Sandra P. Polesky ◽  
Pramote Dechaumphai ◽  
Christopher E. Glass ◽  
Ajay K. Pandey
Keyword(s):  
Structural Analysis ◽  
Three Dimensional ◽  
Leading Edge ◽  
Shock Interference

scholarly journals Transcriptome Analyses of Myometrium from Fibroid Patients Reveals Phenotypic Differences Compared to Non-Diseased Myometrium

2021 ◽  
Vol 22 (7) ◽  
pp. 3618
Author(s):  
Emmanuel N. Paul ◽  
Gregory W. Burns ◽  
Tyler J. Carpenter ◽  
Joshua A. Grey ◽  
Asgerally T. Fazleabas ◽  
...  
Keyword(s):  
Uterine Fibroid ◽  
Three Dimensional ◽  
Uterine Fibroids ◽  
Principal Component ◽  
Leading Edge ◽  
Gene Set Enrichment ◽  
Phenotypic Differences ◽  
False Discovery ◽  
Gene Sets ◽  
High Concordance

Uterine fibroid tissues are often compared to their matched myometrium in an effort to understand their pathophysiology, but it is not clear whether the myometria of uterine fibroid patients represent truly non-disease control tissues. We analyzed the transcriptomes of myometrial samples from non-fibroid patients (M) and compared them with fibroid (F) and matched myometrial (MF) samples to determine whether there is a phenotypic difference between fibroid and non-fibroid myometria. Multidimensional scaling plots revealed that M samples clustered separately from both MF and F samples. A total of 1169 differentially expressed genes (DEGs) (false discovery rate < 0.05) were observed in the MF comparison with M. Overrepresented Gene Ontology terms showed a high concordance of upregulated gene sets in MF compared to M, particularly extracellular matrix and structure organization. Gene set enrichment analyses showed that the leading-edge genes from the TGFβ signaling and inflammatory response gene sets were significantly enriched in MF. Overall comparison of the three tissues by three-dimensional principal component analyses showed that M, MF, and F samples clustered separately from each other and that a total of 732 DEGs from F vs. M were not found in the F vs. MF, which are likely understudied in the pathogenesis of uterine fibroids and could be key genes for future investigation. These results suggest that the transcriptome of fibroid-associated myometrium is different from that of non-diseased myometrium and that fibroid studies should consider using both matched myometrium and non-diseased myometrium as controls.

Three-Dimensional and Rotational Aerodynamics on the NREL Phase VI Wind Turbine Blade

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Alvaro Gonzalez ◽  
Xabier Munduate
Keyword(s):  
Wind Turbine ◽  
Turbine Blade ◽  
Three Dimensional ◽  
Separated Flow ◽  
Leading Edge ◽  
Wind Turbine Blade ◽  
Trailing Edge ◽  
Rotating Blade ◽  
Nrel Phase Vi ◽  
Edge Separation

This work undertakes an aerodynamic analysis over the parked and the rotating NREL Phase VI wind turbine blade. The experimental sequences from NASA Ames wind tunnel selected for this study respond to the parked blade and the rotating configuration, both for the upwind, two-bladed wind turbine operating at nonyawed conditions. The objective is to bring some light into the nature of the flow field and especially the type of stall behavior observed when 2D aerofoil steady measurements are compared to the parked blade and the latter to the rotating one. From averaged pressure coefficients together with their standard deviation values, trailing and leading edge separated flow regions have been found, with the limitations of the repeatability of the flow encountered on the blade. Results for the parked blade show the progressive delay from tip to root of the trailing edge separation process, with respect to the 2D profile, and also reveal a local region of leading edge separated flow or bubble at the inner, 30% and 47% of the blade. For the rotating blade, results at inboard 30% and 47% stations show a dramatic suppression of the trailing edge separation, and the development of a leading edge separation structure connected with the extra lift.

Three-dimensional structural analysis by the integrated force method

1996 ◽  
Vol 58 (5) ◽  
pp. 869-886 ◽  
Author(s):  
I. Kaljević ◽  
S.N. Patnaik ◽  
D.A. Hopkins
Keyword(s):  
Structural Analysis ◽  
Three Dimensional ◽  
Force Method ◽  
Integrated Force Method

Experimental Studies of Leading Edge Contouring Influence on Secondary Losses in Transonic Turbines

2012 ◽  
Author(s):  
Ranjan Saha ◽  
Jens Fridh ◽  
Torsten Fransson ◽  
Boris I. Mamaev ◽  
Mats Annerfeldt
Keyword(s):  
Gas Turbine ◽  
Guide Vane ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Leading Edge ◽  
Secondary Flows ◽  
Noticeable Effect ◽  
Flow Angle ◽  
Wide Range ◽  
Contour Plots

An experimental study of the hub leading edge contouring using fillets is performed in an annular sector cascade to observe the influence of secondary flows and aerodynamic losses. The investigated vane is a three dimensional gas turbine guide vane (geometrically similar) with a mid-span aspect ratio of 0.46. The measurements are carried out on the leading edge fillet and baseline cases using pneumatic probes. Significant precautions have been taken to increase the accuracy of the measurements. The investigations are performed for a wide range of operating exit Mach numbers from 0.5 to 0.9 at a design inlet flow angle of 90°. Data presented include the loading, fields of total pressures, exit flow angles, radial flow angles, as well as profile and secondary losses. The vane has a small profile loss of approximately 2.5% and secondary loss of about 1.1%. Contour plots of vorticity distributions and velocity vectors indicate there is a small influence of the vortex-structure in endwall regions when the leading edge fillet is used. Compared to the baseline case the loss for the filleted case is lower up to 13% of span and higher from 13% to 20% of the span for a reference condition with Mach no. of 0.9. For the filleted case, there is a small increase of turning up to 15% of the span and then a small decrease up to 35% of the span. Hence, there are no significant influences on the losses and turning for the filleted case. Results lead to the conclusion that one cannot expect a noticeable effect of leading edge contouring on the aerodynamic efficiency for the investigated 1st stage vane of a modern gas turbine.

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