scholarly journals Numerical Study of a Rotor/Stator Interaction Case Experimentally Simulated With an Industrial Compressor

2012 ◽  
Author(s):  
Alain Batailly ◽  
Mathias Legrand ◽  
Antoine Millecamps ◽  
Francois Garcin
Keyword(s):  
Numerical Study ◽  
Technical Solution ◽  
Blade Design ◽  
Rotating Blade ◽  
Abradable Coating ◽  
Rotor Stator Interaction ◽  
Blade Tip ◽  
The Impact ◽  
Good Agreement ◽  
Numerical Strategy

Higher aircraft energy efficiency may be achieved by minimizing the clearance between the rotating blade tips and respective surrounding casing. A common technical solution consists in the implementation of an abradable liner which improves both the operational safety and the efficiency of modern turbomachines. Recently, unexpected abradable wear removal mechanisms were observed in experimental set-ups and during maintenance procedures. The present study introduces a numerical strategy capable to address this occurrence. After focusing on the analysis of the experimental results, the good agreement between experimental observations and numerical results is illustrated in terms of critical stress levels within the blade as well as final wear profiles of the abradable liner. New blade designs are also explored in order to assess the impact of blade design on the outbreak of the interaction phenomenon. The prevalence of three dominant parameters in the interaction onset is shown: (1) blade design, (2) abradable material mechanical properties and (3) the need for a global distortion of the casing to synchronize blade-tip/abradable coating contacts.

scholarly journals Numerical-Experimental Comparison in the Simulation of Rotor/Stator Interaction Through Blade-Tip/Abradable Coating Contact

2012 ◽  
Vol 134 (8) ◽  
Author(s):  
Alain Batailly ◽  
Mathias Legrand ◽  
Antoine Millecamps ◽  
François Garcin
Keyword(s):  
Experimental Comparison ◽  
Technical Solution ◽  
Numerical Predictions ◽  
Rotating Blade ◽  
Abradable Coating ◽  
Highly Sensitive ◽  
Rotor Stator Interaction ◽  
Blade Tip ◽  
Good Agreement ◽  
Numerical Strategy

Higher aircraft energy efficiency may be achieved by minimizing the clearance between the rotating blade tips and respective surrounding casing. A common technical solution consists in the implementation of an abradable liner which improves both the operational safety and the efficiency of modern turbomachines. However, unexpected abradable wear removal mechanisms were recently observed in experimental set-ups as well as during maintenance procedures. Based on a numerical strategy previously developed, the present study introduces a numerical-experimental comparison of such occurrence. Attention is first paid to the review and analysis of existing experimental results. Good agreement with numerical predictions is then illustrated in terms of critical stress levels within the blade as well as final wear profiles of the abradable liner. Numerical results suggest an alteration of the abradable mechanical properties in order to explain the outbreak of a divergent interaction. New blade designs are also explored in this respect and it is found that the interaction phenomenon is highly sensitive to (1) the blade geometry, (2) the abradable material properties, and (3) the distortion of the casing.

Implementation of a Rig Test for Rotor/Stator Interaction of Low-Pressure Compressor Blades and Comparison of Experimental Results With Numerical Model

2020 ◽  
Author(s):  
Laura Pacyna ◽  
Alexandre Bertret ◽  
Alain Derclaye ◽  
Luc Papeleux ◽  
Jean-Philippe Ponthot
Keyword(s):  
Low Cost ◽  
Low Pressure ◽  
Angular Speed ◽  
Compressor Blades ◽  
Abradable Coating ◽  
Rotor Stator Interaction ◽  
Blade Tip ◽  
Numerical Tool ◽  
Short Time ◽  
Pressure Compressor

Abstract To investigate the contact phenomenon between the blade tip and the abradable coated casing, a rig test was designed and built. This rig test fills the following constraints: simplification of the low-pressure compressor environment but realistic mechanical conditions, ability to test several designs in short time, at low cost and repeatability. The rig test gives the opportunity to investigate the behavior of different blade designs regarding the sought phenomenon, to refine and mature the phenomenon comprehension and to get data for the numerical tool validation. The numerical tool considers a 3D finite elements model of low-pressure compressor blades with a surrounding rigid casing combined with a specialized model to take into account the effects of the wear of the abradable coating on the blade dynamics. Numerical results are in good agreement with tests in terms of: critical angular speed, blade dynamics and wear pattern on the abradable coated casing.

scholarly journals Thermo-Mechanical Modeling of Abradable Coating Wear in Aircraft Engines

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Florence Nyssen ◽  
Alain Batailly
Keyword(s):  
Numerical Modeling ◽  
Thermal Effects ◽  
Small Time ◽  
Technical Solution ◽  
Contact Interactions ◽  
Time Step ◽  
Element Mesh ◽  
Mechanical Coupling ◽  
Abradable Coating ◽  
The Impact

In modern turbomachine designs, the nominal clearances between rotating bladed-disks and their surrounding casing are reduced to improve aerodynamic performances of the engine. This clearance reduction increases the risk of contacts between components and may lead to hazardous interaction phenomena. A common technical solution to mitigate such interactions consists in the deposition of an abradable coating along the casing inner surface. This enhances the engine efficiency while ensuring operational safety. However, contact interactions between blade tips and an abradable layer may yield unexpected wear removal phenomena. The aim of this work is to investigate the numerical modeling of thermal effects within the abradable layer during contact interactions and compare it with experimental data. A dedicated thermal finite element mesh is employed. At each time-step, a weak thermo-mechanical coupling is assumed: thermal effects affect the mechanics of the system, but the mechanical deformation of the elements has no effect on temperatures. Weak coupling is well appropriated in the case of rapid dynamics using small time-step and explicit resolution schemes. Moreover, only heat transfer by conduction is considered in this work. To reduce computational times, a coarser spatial discretization is used for the thermal mesh comparing to the mechanical one. The time-step used to compute the temperature evolution is larger than the one used for the mechanical iterations since the time constant of thermal effect is larger than contact events. The proposed numerical modeling strategy is applied on an industrial blade to analyze the impact of thermal effects on the blade's dynamics.

Numerical Simulation of Single Thruster in Open Water

2017 ◽  
Author(s):  
Qin Zhang ◽  
Peifeng Ma ◽  
Jing Liu ◽  
Rajeev Kumar Jaiman
Keyword(s):  
Numerical Data ◽  
Open Water ◽  
Wake Flow ◽  
Dynamic Positioning ◽  
Floating Structure ◽  
Structured Grid ◽  
Rotating Blade ◽  
Blade Tip ◽  
Steady State Simulation ◽  
Good Agreement

The flow interaction between a dynamic positioning (DP) thruster and a floating structure (semi-submersible) hull attracted quite a lot of attention in recent years. In this study, the Spalart-Allmaras RANS model has been evaluated to simulate single thruster rotated in the open water with OpenFOAM. The actual thruster geometry has been meshed with structured grid, and the gap between the blade tip and nozzle is carefully treated. The Moving Reference Frame (MRF) method is used for steady-state simulation, and the arbitrary mesh interface (AMI) method is applied to simulate the rotating blade for transient dynamic mesh simulation. The numerical results are compared with available experimental and numerical data, especially in the wake flow. Good agreement is shown in this study.

Effect of blade tip grooving on the performance of an axial fan at different tip clearances in the absence and presence of inlet guide vanes

2019 ◽  
Vol 234 (1) ◽  
pp. 72-84
Author(s):  
Masoud Kharati-Koopaee ◽  
Hossein Moallemi
Keyword(s):  
Numerical Study ◽  
Guide Vane ◽  
Pressure Coefficient ◽  
Tip Clearance ◽  
Axial Fan ◽  
Guide Vanes ◽  
Inlet Guide Vanes ◽  
Blade Tip ◽  
Torque Coefficient ◽  
The Impact

This research aims at the numerical study of the blade tip grooving effect on the performance of a ducted axial fan at different tip clearances in the absence and presence of inlet guide vanes. To do this, significant parameters of the fan (i.e. pressure and torque coefficients as well as fan efficiency) comprising single- and double-grooved tips are evaluated and compared with those of the original fan. Validation of the considered numerical model is performed through comparison of the numerical findings with experimental results of a single-stage ducted fan, which comprises a set of 37 guide vane and 24-blade rotor rotating at the speed of 3600 r/min. Results reveal that grooving the blade tip causes the fan parameters to increase and higher fan parameters could be attained adopting single-grooved tip. It is shown that employing grooved blades causes the sensitivity of fan parameters to the change in the tip clearance to diminish. Results exhibit that the impact of grooving the blade on the reduction of sensitivity of fan parameters to the change in the tip clearance for the single-grooved tip in the absence of guide vanes is more remarkable than the other cases and in this case, as the tip clearance increases from the lower to the upper considered value, the decreased percentages in pressure coefficient, torque coefficient, and fan efficiency are 29.8%, 8.9%, and 22.8%, respectively. Numerical findings show that the influence of grooving the blade on the fan parameters in the presence of guide vanes is lower than that without guide vanes and in the presence of guide vanes, the highest average increase percentages in pressure coefficient, torque coefficient, and fan efficiency relative to those of the original fan, which is observed in the single grooved tip, are 3.1%, 1.4%, and 1.7%, respectively.

scholarly journals Full Three-Dimensional Rotor/Stator Interaction Simulations in Aircraft Engines With Time-Dependent Angular Speed

2016 ◽  
Vol 139 (3) ◽  
Author(s):  
Alain Batailly ◽  
Mathias Legrand ◽  
Christophe Pierre
Keyword(s):  
Three Dimensional ◽  
Aircraft Engine ◽  
Angular Speed ◽  
Industrial Test ◽  
Numerical Results ◽  
Time Dependent ◽  
Abradable Coating ◽  
Acceleration And Deceleration ◽  
Rotor Stator Interaction ◽  
Numerical Strategy

Modern aircraft engine designs feature reduced clearances that may initiate structural contacts between rotating and static components. A numerical strategy dedicated to the simulation of such interactions is here enriched in order to account for time-dependent angular speeds. This contribution first details the evolution of the numerical strategy before validating the developments by comparing numerical results with experimental observations made on an industrial test bench. Further, numerical investigations allow to assess the sensitivity of the numerical results to acceleration and deceleration rates. The results, obtained with and without abradable coating, underline the fundamental nonlinear nature of the analyzed system. It is found that the lower acceleration rates favor the arisal of interaction phenomena, and that the amplitudes of vibration at a given angular speed are generally lower when the blade decelerates.

scholarly journals Numerical Simulation of Tool/Abradable Material Interaction Experiments

2012 ◽  
Author(s):  
Alain Batailly ◽  
Marion Cuny ◽  
Mathias Legrand
Keyword(s):  
Strain Rate ◽  
High Speed ◽  
Rate Dependence ◽  
Strain Rate Dependence ◽  
Robust Solution ◽  
Abradable Coating ◽  
Rotor Stator Interaction ◽  
Material Interaction ◽  
Numerical Strategy

Applying abradable coating on the casing of turbomachines has been widely recognized as a robust solution advantageously combining the adjustment of operating clearances with the reduction of potential non-repairable damages. Thus, the modeling of this material is a growing field of investigation. Based on the numerical strategy proposed and detailed in previous publication by the same authors, the present study aims at capturing the mechanical behavior of abradable coating in the context of high speed interaction with a rigid tool. The plastic law given is first enriched in order to take into account strain rate dependence. The sensitivity of the model regarding its main numerical parameters is assessed and highlights the role of each of these parameters. The calibration of numerical results with respect to experimental results lead to very satisfying results that confirm that the proposed strategy is well-suited for the modeling of abradable coating. Finally, the newly developped viscoplastic law is applied to a 3D rotor/stator interaction case to determine the criticity of strain rate dependence in the case of blade/casing contact.

scholarly journals Thermomechanical Modelling of a Steel Plate Impacted by a Shot and Experimental Validation

2006 ◽  
Vol 524-525 ◽  
pp. 167-172 ◽  
Author(s):  
Sébastien Rouquette ◽  
Emmanuelle Rouhaud ◽  
Hervé Pron ◽  
Manuel François ◽  
Christian Bissieux ◽  
...  
Keyword(s):  
Temperature Rise ◽  
Experimental Validation ◽  
Steel Plate ◽  
Numerical Study ◽  
Infrared Camera ◽  
Metallic Plate ◽  
Mechanical Problem ◽  
The Impact ◽  
Compressive Residual Stresses ◽  
Good Agreement

This work presents an experimental and numerical study of the thermo-mechanical problem of a steel plate impacted by a shot. The temperature rise is estimated and its effect on the compressive residual stress is analyzed. The simulations show that the value of the compressive residual stresses at the surface of the plate is modified when thermo-mechanical effects are included in the model as compared with simulation including hardening effects only. To validate this numerical study, an experimental device has been developed to measure the temperature rise after the impact. The experiment consists of the impact of a shot on a metallic plate. The temperature measurement is performed by an infrared camera located on the side of the plate opposite to the impact. Comparison between these experimental measurements and the numerical solution gives good agreement (to within 5%).

scholarly journals Full 3D Rotor/Stator Interaction Simulations in Aircraft Engines With Time-Dependent Angular Speed

2016 ◽  
Author(s):  
Alain Batailly ◽  
Mathias Legrand ◽  
Christophe Pierre
Keyword(s):  
Aircraft Engine ◽  
Angular Speed ◽  
Industrial Test ◽  
Numerical Results ◽  
Time Dependent ◽  
Abradable Coating ◽  
Acceleration And Deceleration ◽  
Rotor Stator Interaction ◽  
Nonlinear Nature ◽  
Numerical Strategy

Modern aircraft engine designs feature reduced clearances that may initiate structural contacts between rotating and static components. A numerical strategy dedicated to the simulation of such interactions is here enriched in order to account for time-dependent angular speeds. This contribution first details the evolution of the numerical strategy before validating the developments by comparing numerical results with experimental observations made on an industrial test bench. Further numerical investigations allow to assess the sensitivity of numerical results to acceleration and deceleration rates. Results, obtained with and without abradable coating, underline the fundamental nonlinear nature of the analysed system. It is found that lower acceleration rates favour the arisal of interaction phenomena and that amplitudes of vibration at a given angular speed are generally lower when the blade decelerates.

A Combined Experimental and Numerical Study of the Turbine Blade Tip Film Cooling Effectiveness Under Rotation Condition

2014 ◽  
Author(s):  
M. Rezasoltani ◽  
K. Lu ◽  
M. T. Schobeiri ◽  
J. C. Han
Keyword(s):  
Film Cooling ◽  
Numerical Study ◽  
Experimental Investigations ◽  
Pressure Side ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Side Edge ◽  
Blade Tip ◽  
The Impact ◽  
Compound Angle

Detailed numerical and experimental investigations of film cooling effectiveness were conducted on the blade tips of the first rotor row pertaining to a three-stage research turbine. Four different blade tip ejection configurations were utilized to determine the impact of the hole arrangements on the film cooling effectiveness. plane tip with tip hole cooling, squealer tip with tip hole cooling, plane tip with pressure-side-edge compound angle hole cooling and squealer tip with pressure-side-edge compound angle hole cooling. To avoid rotor imbalance, every pair is installed radially. Film cooling effectiveness measurements were performed for three blowing ratios (M) of 0.75, 1.25 and 1.75. Film cooling data was also obtained for three rotational speeds; 3000 rpm (reference condition), 2550 rpm and 2000 rpm. Film cooling measurements were performed using pressure sensitive paint (PSP) technique. In a parallel effort, extensive numerical investigations of the above configurations were performed to give a better view of flow behavior using a commercially available code. The experimental investigations were performed in the three-stage multi-purpose turbine research facility at the Turbomachinery Performance and Flow Research Laboratory (TPFL), Texas A&M University.

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