====== NASA Rotor 37 ====== * [[#tab-fr|Français]] * [[#tab-en|English]] This page contains various informations associated to one of the rotor 37 blade model used in LAVA publications. Downloadable files **[[https://gitlab.lava.polymtl.ca/depots_publics/modeles/nasa/rotor37|Git project]]** ===== Original model ===== * Original technical report [(cite:reid1978design>Reid. «Design and overall performance of four highly loaded, high speed inlet stages for an advanced high-pressure-ratio core compressor » 1978. {{ https://ntrs.nasa.gov/citations/19780025165|pdf}})]: @TechReport{reid1978design, author = {Reid, L. and Moore, R. D.}, title = {Design and overall performance of four highly loaded, high speed inlet stages for an advanced high-pressure-ratio core compressor}, institution = {NASA Lewis Research Center Cleveland, OH, United States}, note = {NASA-TP-1337, url~: \url{https://ntrs.nasa.gov/citations/19780025165}, 1978 (accessed 2020-10-29)}} * Pictures : {{ ..:r37_1.png?nolink&350 |}} Fig1. https://catalog.archives.gov/id/17468361 {{ ..:r37_2.png?nolink&325 |}} Fig2. https://catalog.archives.gov/id/17468389 @Misc{huebler1977records, author = {Huebler, D.}, title = {Rotor 37 and stator 37 assembly. {R}ecords of the {N}ational {A}eronautics and {S}pace {A}dministration, 1903 - 2006. {P}hotographs relating to agency activities, facilities and personnel, 1973 - 2013}, note = {\href{https://catalog.archives.gov/id/17468361}{https://catalog.archives.gov/id/17468361}, 1977 (accessed 2020-10-29)}, % for Fig. 1 note = {\href{https://catalog.archives.gov/id/17468389}{https://catalog.archives.gov/id/17468389}, 1977 (accessed 2020-10-29)}, % for Fig. 2} ===== Finite element mesh ===== * Number of nodes: 5745 * Total number of elements: 1800 * Number of degrees of freedom: 16524 * Element type: quadratic pentahedron {{ ..:r37_mesh_mz.png?nolink&250 }} finite element mesh overview (coarse mesh) * Number of nodes: 20657 * Total number of elements: 6664 * Number of degrees of freedom: 60588 * Element type: quadratic pentahedron {{ ..:rotor_37:rotor37_mz_fine.png?nolink&250 }} finite element mesh overview (refined mesh) - {{ :public:modeles:rotor_37:r37.zip |LaTeX source files}} ===== Material properties ===== * Rotor 37 is made of a 200-grade maraging steel [(cite:reid1978design>Reid. «Design and overall performance of four highly loaded, high speed inlet stages for an advanced high-pressure-ratio core compressor » 1978. {{ https://ntrs.nasa.gov/citations/19780025165|pdf}})] * Considered properties : 18-Ni 200-maraging alloy [(cite:colaitis2021harmonic>Colaïtis. «The harmonic balance method with arc-length continuation in blade-tip/casing contact problems » 2021. {{ https://doi.org/10.1016/j.jsv.2021.116070|doi}}/{{ https://hal.archives-ouvertes.fr/hal-03180361v2|oai}})] [(cite:piollet2019blade>Piollet. «Blade/casing rubbing interactions in aircraft engines: Numerical benchmark and design guidelines based on NASA rotor 37 » 2019. {{ https://doi.org/10.1016/j.jsv.2019.114878|doi}}/{{ https://hal.archives-ouvertes.fr/hal-02281666|oai}})]: - Young's modulus E = 180 GPa - density$\rho$ = 8000 kg/m3 - Poisson's ratio $\nu$ = 0.3 - yield stress $\sigma_Y$ = 1.38 GPa (200 000 psi) * First three predicted natural frequencies (with clamped root) for the coarse mesh: - 1B: 5272.3 rad/s / 839.1 Hz - 1T: 15760.5 rad/s / 2508.4 Hz - 2B: 19071.3 rad/s / 3035.3 Hz * First three predicted natural frequencies (with clamped root) for the refined mesh: - 1B: 5368.7 rad/s / 838.5 Hz - 1T: 15754.7 rad/s / 2507.4 Hz - 2B: 19032.9 rad/s / 3029.2 Hz ===== Featured articles from the LAVA ===== * //The harmonic balance method with arc-length continuation in blade-tip/casing contact problems// [(cite:colaitis2021harmonic>Colaïtis. «The harmonic balance method with arc-length continuation in blade-tip/casing contact problems » 2021. {{ https://doi.org/10.1016/j.jsv.2021.116070|doi}}/{{ https://hal.archives-ouvertes.fr/hal-03180361v2|oai}})] BibTex @Article{colaitis2021harmonic, author = {Cola\"{i}tis, Y. and Batailly, A}, title = {{The harmonic balance method with arc-length continuation in blade-tip/casing contact problems}}, journal = {J. Sound Vib.}, year = {2021}, volume = {502}, pages = {116070}, issn = {0022-460X}, note = {\href{https://doi.org/10.1016/j.jsv.2021.116070}{doi~: 10.1016/j.jsv.2021.116070} - \href{https://hal.archives-ouvertes.fr/hal-03163560}{oai: hal-03163560}}, abstract = {This article presents a Harmonic Balance Method-based numerical strategy to provide a qualitative numerical characterization of a compressor blade’s dynamics when structural contacts occur with the surrounding casing. The mitigation of the Gibbs phenomenon follows a two-pronged approach: (1) a regularization of the unilateral contact law and (2) the adjustment of the Fourier coefficients by means of a Lanczos filtering technique. In order to validate the proposed approach, it is first applied to an academic cantilever rod undergoing unilateral contact constraints. An in-depth comparative analysis of the obtained results—with an emphasis on displacements, contact forces and velocities—with respect to a time integration-based reference numerical strategy underlines the relevance and accuracy of the proposed methodology. The latter is then applied to the vibration analysis of an industrial compressor blade: NASA rotor 37. For a given contact configuration, obtained results are thoroughly compared to those obtained with a previously published time integration-based numerical strategy with a distinct contact treatment algorithm. Particular attention is paid to demonstrate the accuracy of the methodology for the prediction of displacements, contact forces, velocities as well as stress fields within the blade. Notably, it is evidenced that the proposed methodology, contrary to the reference time integration-based numerical strategy, is able to capture the exact location of the blade’s nonlinear resonance.}} * //Blade/casing rubbing interactions in aircraft engines: Numerical benchmark and design guidelines based on NASA rotor 37// [(cite:piollet2019blade>Piollet. «Blade/casing rubbing interactions in aircraft engines: Numerical benchmark and design guidelines based on NASA rotor 37 » 2019. {{ https://doi.org/10.1016/j.jsv.2019.114878|doi}}/{{ https://hal.archives-ouvertes.fr/hal-02281666|oai}})] BibTex @Article{piollet2019blade, author = {Piollet, E. and Nyssen, F. and Batailly, A.}, title = {Blade/casing rubbing interactions in aircraft engines: Numerical benchmark and design guidelines based on NASA rotor 37}, journal = {J. Sound Vib.}, year = {2019}, volume = {460}, pages = {114878}, issn = {0022-460X}, note = {\href{https://doi.org/10.1016/j.jsv.2019.114878}{doi~: 10.1016/j.jsv.2019.114878} - \href{https://hal.archives-ouvertes.fr/hal-02281666}{oai: hal-02281666}}, abstract = {In order to improve the efficiency of aircraft engines, the reduction of clearances between blade tips and their surrounding casing is one avenue manufacturers consider to lower aerodynamic losses. This reduction increases the risk of blade tip/casing contact interactions under nominal operating conditions. Designers need tools to accurately predict subsequent nonlinear vibrations. Engineers and researchers have developed a variety of sophisticated numerical models to predict blades' responses. These models are related to distinct frameworks (time/frequency domain) and various solution algorithms (explicit/implicit time integration schemes, penalty/Lagrange multiplier contact treatment…) which calls for comparative analyses. However, published results are often limited for the sake of confidentiality thus preventing any detailed confrontation. While qualitative understanding can be gained from simplified academic models, full scale models are needed to predict complex interactions in a realistic manner. In this context, this paper proposes a benchmark featuring detailed simulations and analyses of a full 3D finite element model based on the open NASA rotor 37 compressor blade to facilitate reproducibility and collaboration across the research community. NASA rotor 37, a compressor stage widely used as a test case in aerodynamic simulations and validations, has the advantage of presenting a realistic blade geometry. The geometry of the blade is built from publicly available reports. The paper provides details on the geometry, the numerical model and the results to allow an easy use of this model across the fields of structural dynamics. Two contact scenarios are investigated: one with direct contact against the casing, and one with abradable material deposited on the casing to mitigate contact severity through wear. The nonlinear vibration response of the blade is simulated in the time domain. It is evidenced that the addition of the abradable material decreases the amplitude of vibration for most of the angular speeds investigated. However, new interactions appear for some angular speeds. The obtained results are consistent with previous simulations on industrial geometries. Based on works showing improved aerodynamic performances when the blade is tilted, a total of seven geometries are investigated: the reference blade, with a straight vertical stacking line similar to the original rotor 37, two forward-leaned blades, two backward-swept blades and two full forward chordwise swept blades. The sweep and lean variations are shown to have a dramatic impact on the vibration response: the backward sweep results in an increased blade's robustness to contact events and the full forward chordwise sweep in a reduced robustness, while the forward lean leads to a robustness similar to the reference blade.}} Cette page contient diverses informations associées à l'un des modèles de l'aube NASA rotor 37 utilisé dans les publications du LAVA. Fichiers téléchargeables **[[https://gitlab.lava.polymtl.ca/depots_publics/modeles/nasa/rotor37|lien vers le projet Git]]** ===== Modèle original ===== * Rapport technique original [(cite:reid1978design>Reid. «Design and overall performance of four highly loaded, high speed inlet stages for an advanced high-pressure-ratio core compressor » 1978. {{ https://ntrs.nasa.gov/citations/19780025165|pdf}})]: @TechReport{reid1978design, author = {Reid, L. and Moore, R. D.}, title = {Design and overall performance of four highly loaded, high speed inlet stages for an advanced high-pressure-ratio core compressor}, institution = {NASA Lewis Research Center Cleveland, OH, United States}, note = {NASA-TP-1337, url~: \url{https://ntrs.nasa.gov/citations/19780025165}, 1978 (accessed 2020-10-29)}} * Photographies : {{ ..:r37_1.png?nolink&350 |}} Fig1. https://catalog.archives.gov/id/17468361 {{ ..:r37_2.png?nolink&325 |}} Fig2. https://catalog.archives.gov/id/17468389 @Misc{huebler1977records, author = {Huebler, D.}, title = {Rotor 37 and stator 37 assembly. {R}ecords of the {N}ational {A}eronautics and {S}pace {A}dministration, 1903 - 2006. {P}hotographs relating to agency activities, facilities and personnel, 1973 - 2013}, note = {\href{https://catalog.archives.gov/id/17468361}{https://catalog.archives.gov/id/17468361}, 1977 (accessed 2020-10-29)}, % for Fig. 1 note = {\href{https://catalog.archives.gov/id/17468389}{https://catalog.archives.gov/id/17468389}, 1977 (accessed 2020-10-29)}, % for Fig. 2} ===== Maillage éléments finis ===== * Nombre de noeuds : 5745 * Nombre total d'éléments : 1800 * Nombre de degrés de liberté : 16524 * Type d'élément : pentaèdre quadratique {{ ..:r37_mesh_mz.png?nolink&250 }} aperçu du maillage éléments finis (maillage grossier) * Nombre de noeuds : 20657 * Nombre total d'éléments : 6664 * Nombre de degrés de liberté : 60588 * Type d'élément : pentaèdre quadratique {{ ..:rotor_37:rotor37_mz_fine.png?nolink&250 }} aperçu du maillage éléments finis (maillage fin) - {{ :public:modeles:rotor_37:r37.zip |sources LaTeX}} ===== Propriétés matériau ===== * Le matériau du rotor 37 est un alliage à base de nickel : un acier maraging de grade 200 [(cite:reid1978design>Reid. «Design and overall performance of four highly loaded, high speed inlet stages for an advanced high-pressure-ratio core compressor » 1978. p64 {{ https://ntrs.nasa.gov/citations/19780025165|pdf}})] * Propriétés considérées : alliage 18-Ni 200-maraging [(cite:colaitis2021harmonic>Colaïtis. «The harmonic balance method with arc-length continuation in blade-tip/casing contact problems » 2021. {{ https://doi.org/10.1016/j.jsv.2021.116070|doi}}/{{ https://hal.archives-ouvertes.fr/hal-03180361v2|oai}})] [(cite:piollet2019blade>Piollet. «Blade/casing rubbing interactions in aircraft engines: Numerical benchmark and design guidelines based on NASA rotor 37 » 2019. {{ https://doi.org/10.1016/j.jsv.2019.114878|doi}}/{{ https://hal.archives-ouvertes.fr/hal-02281666|oai}})]: - Module d'Young E = 180 GPa - masse volumique $\rho$ = 8000 kg/m3 - coefficient de Poisson $\nu$ = 0,3 - limite élastique $\sigma_Y$ = 1,38 GPa (200 000 psi) * Trois premiers modes prévus (noeuds de la base encastrés) pour le maillage grossier : - 1F : 5272,3 rad/s / 839,1 Hz - 1T : 15760,5 rad/s / 2508,4 Hz - 2F : 19071,3 rad/s / 3035,3 Hz * Trois premiers modes prévus (noeuds de la base encastrés) pour le maillage fin : - 1F : 5268,7 rad/s / 838,5 Hz - 1T : 15754,7 rad/s / 2507,4 Hz - 2F : 19032,9 rad/s / 3029,2 Hz ===== Articles du laboratoire ===== * //The harmonic balance method with arc-length continuation in blade-tip/casing contact problems// [(cite:colaitis2021harmonic>Colaïtis. «The harmonic balance method with arc-length continuation in blade-tip/casing contact problems » 2021. {{ https://doi.org/10.1016/j.jsv.2021.116070|doi}}/{{ https://hal.archives-ouvertes.fr/hal-03180361v2|oai}})] BibTex @Article{colaitis2021harmonic, author = {Cola\"{i}tis, Y. and Batailly, A}, title = {{The harmonic balance method with arc-length continuation in blade-tip/casing contact problems}}, journal = {J. Sound Vib.}, year = {2021}, volume = {502}, pages = {116070}, issn = {0022-460X}, note = {\href{https://doi.org/10.1016/j.jsv.2021.116070}{doi~: 10.1016/j.jsv.2021.116070} - \href{https://hal.archives-ouvertes.fr/hal-03163560}{oai: hal-03163560}}, abstract = {This article presents a Harmonic Balance Method-based numerical strategy to provide a qualitative numerical characterization of a compressor blade’s dynamics when structural contacts occur with the surrounding casing. The mitigation of the Gibbs phenomenon follows a two-pronged approach: (1) a regularization of the unilateral contact law and (2) the adjustment of the Fourier coefficients by means of a Lanczos filtering technique. In order to validate the proposed approach, it is first applied to an academic cantilever rod undergoing unilateral contact constraints. An in-depth comparative analysis of the obtained results—with an emphasis on displacements, contact forces and velocities—with respect to a time integration-based reference numerical strategy underlines the relevance and accuracy of the proposed methodology. The latter is then applied to the vibration analysis of an industrial compressor blade: NASA rotor 37. For a given contact configuration, obtained results are thoroughly compared to those obtained with a previously published time integration-based numerical strategy with a distinct contact treatment algorithm. Particular attention is paid to demonstrate the accuracy of the methodology for the prediction of displacements, contact forces, velocities as well as stress fields within the blade. Notably, it is evidenced that the proposed methodology, contrary to the reference time integration-based numerical strategy, is able to capture the exact location of the blade’s nonlinear resonance.}} * //Blade/casing rubbing interactions in aircraft engines: Numerical benchmark and design guidelines based on NASA rotor 37// [(cite:piollet2019blade>Piollet. «Blade/casing rubbing interactions in aircraft engines: Numerical benchmark and design guidelines based on NASA rotor 37 » 2019. {{ https://doi.org/10.1016/j.jsv.2019.114878|doi}}/{{ https://hal.archives-ouvertes.fr/hal-02281666|oai}})] BibTex @Article{piollet2019blade, author = {Piollet, E. and Nyssen, F. and Batailly, A.}, title = {Blade/casing rubbing interactions in aircraft engines: Numerical benchmark and design guidelines based on NASA rotor 37}, journal = {J. Sound Vib.}, year = {2019}, volume = {460}, pages = {114878}, issn = {0022-460X}, note = {\href{https://doi.org/10.1016/j.jsv.2019.114878}{doi~: 10.1016/j.jsv.2019.114878} - \href{https://hal.archives-ouvertes.fr/hal-02281666}{oai: hal-02281666}}, abstract = {In order to improve the efficiency of aircraft engines, the reduction of clearances between blade tips and their surrounding casing is one avenue manufacturers consider to lower aerodynamic losses. This reduction increases the risk of blade tip/casing contact interactions under nominal operating conditions. Designers need tools to accurately predict subsequent nonlinear vibrations. Engineers and researchers have developed a variety of sophisticated numerical models to predict blades' responses. These models are related to distinct frameworks (time/frequency domain) and various solution algorithms (explicit/implicit time integration schemes, penalty/Lagrange multiplier contact treatment…) which calls for comparative analyses. However, published results are often limited for the sake of confidentiality thus preventing any detailed confrontation. While qualitative understanding can be gained from simplified academic models, full scale models are needed to predict complex interactions in a realistic manner. In this context, this paper proposes a benchmark featuring detailed simulations and analyses of a full 3D finite element model based on the open NASA rotor 37 compressor blade to facilitate reproducibility and collaboration across the research community. NASA rotor 37, a compressor stage widely used as a test case in aerodynamic simulations and validations, has the advantage of presenting a realistic blade geometry. The geometry of the blade is built from publicly available reports. The paper provides details on the geometry, the numerical model and the results to allow an easy use of this model across the fields of structural dynamics. Two contact scenarios are investigated: one with direct contact against the casing, and one with abradable material deposited on the casing to mitigate contact severity through wear. The nonlinear vibration response of the blade is simulated in the time domain. It is evidenced that the addition of the abradable material decreases the amplitude of vibration for most of the angular speeds investigated. However, new interactions appear for some angular speeds. The obtained results are consistent with previous simulations on industrial geometries. Based on works showing improved aerodynamic performances when the blade is tilted, a total of seven geometries are investigated: the reference blade, with a straight vertical stacking line similar to the original rotor 37, two forward-leaned blades, two backward-swept blades and two full forward chordwise swept blades. The sweep and lean variations are shown to have a dramatic impact on the vibration response: the backward sweep results in an increased blade's robustness to contact events and the full forward chordwise sweep in a reduced robustness, while the forward lean leads to a robustness similar to the reference blade.}}