Structural Evaluation and Testing of Swept Compressor Rotor

1994 ◽  
Vol 116 (1) ◽  
pp. 217-222 ◽  
Author(s):  
S. Aksoy ◽  
B. Mitlin ◽  
H. Borowy
Keyword(s):  
Three Dimensional ◽  
Compressor Blade ◽  
Dimensional Structure ◽  
Element Analysis ◽  
Turbine Engine ◽  
Compressor Rotor ◽  
Structural Evaluation ◽  
Critical Issues ◽  
Stress Prediction ◽  
Design Speed

This paper summarizes specific critical issues encountered in the structural analysis of a swept first-stage compressor blade of a gas turbine engine and the results of the test to evaluate the accuracy of the modeling and surface stress prediction procedure. The surface stresses of a three-dimensional structure were obtained using membrane elements attached to the surface of solid elements. Steady stress measurements were then made during accelerations and decelerations to and from design speed. The test was conducted in an evacuated spin rig. The measurements were used to evaluate the validity of the stress prediction from finite element analysis.

Auxetic deformation of the weft-knitted Miura-ori fold

2019 ◽  
Vol 90 (5-6) ◽  
pp. 617-630
Author(s):  
Kun Luan ◽  
Andre West ◽  
Emiel DenHartog ◽  
Marian McCord
Keyword(s):  
Deformation Mechanism ◽  
Poisson’S Ratio ◽  
Three Dimensional ◽  
Poisson's Ratio ◽  
Dimensional Structure ◽  
Damping Capacity ◽  
Analysis Model ◽  
Element Analysis ◽  
Specific Direction ◽  
Application Fields

Negative Poisson’s ratio (NPR) material with unique geometry is rare in nature and has an auxetic response under strain in a specific direction. With this unique property, this type of material is significantly promising in many specific application fields. The curling structure commonly exists in knitted products due to the unbalanced force inside a knit loop. Thus, knitted fabric is an ideal candidate to mimic natural NPR materials, since it possesses such an inherent curly configuration and the flexibility to design and process. In this work, a weft-knitted Miura-ori fold (WMF) fabric was produced that creates a self-folding three-dimensional structure with NPR performance. Also, a finite element analysis model was developed to simulate the structural auxetic response to understand the deformation mechanism of hierarchical thread-based auxetic fabrics. The simulated strain–force curves of four WMF fabrics quantitatively agree with our experimental results. The auxetic morphologies, Poisson’s ratio and damping capacity were discussed, revealing the deformation mechanism of the WMF fabrics. This study thus provides a fundamental framework for mechanical-stimulating textiles. The developed NPR knitted fabrics have a high potential to be employed in areas of tissue engineering, such as artificial blood vessels and artificial folding mucosa.

scholarly journals Assessment of Mechanical Design Parameters for an Aero Gas Turbine Engine Jet Pipe Casing using Finite Element Analysis

2020 ◽  
Vol 9 (5) ◽  
pp. 1197-1201
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Gas Turbine ◽  
Mechanical Design ◽  
Three Dimensional ◽  
Gas Turbine Engine ◽  
Design Parameters ◽  
Element Analysis ◽  
Engine Operation ◽  
Turbine Engine

Aero Gas Turbine engines power aircrafts for civil transport application as well as for military fighter jets. Jet pipe casing assembly is one of the critical components of such an Aero Gas Turbine engine. The objective of the casing is to carry out the required aerodynamic performance with a simultaneous structural performance. The Jet pipe casing assembly located in the rear end of the engine would, in case of fighter jet, consist of an After Burner also called as reheater which is used for thrust augmentation to meet the critical additional thrust requirement as demanded by the combat environment in the war field. The combustion volume for the After burner operation together with the aerodynamic conditions in terms of pressure, temperature and optimum air velocity is provided by the Jet pipe casing. While meeting the aerodynamic requirements, the casing is also expected to meet the structural requirements. The casing carries a Convergent-Divergent Nozzle in the downstream side (at the rear end) and in the upstream side the casing is attached with a rear mount ring which is an interface between engine and the airframe. The mechanical design parameters involving Strength reserve factors, Fatigue Life, Natural Frequencies along with buckling strength margins are assessed while the Jet pipe casing delivers the aerodynamic outputs during the engine operation. A three dimensional non linear Finite Element analysis of the Jet pipe casing assembly is carried out, considering the up & down stream aerodynamics together with the mechanical boundary conditions in order to assess the Mechanical design parameters.

Impact of Sweep on Part Speed Performance of an Axial Compressor Rotor With Circumferential Casing Grooves

2019 ◽  
Author(s):  
Shraman Goswami ◽  
M. Govardhan
Keyword(s):  
Flow Field ◽  
High Performance ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Field Investigation ◽  
Performance Comparison ◽  
Rotor Blades ◽  
Stall Margin ◽  
Compressor Rotor ◽  
Design Speed

Abstract High performance and increased operating range of an axial compressor is obtained by employing three-dimensional design features, such as sweep, as well as shroud casing treatments, such as circumferential casing grooves. A number of different rotor blades with different amounts of sweeps and different sweep starting spans are studied at design speed. Different swept rotors, including zero sweep, are derived from Rotor37 rotor geometry. In the current study the best performing rotor with sweep is analyzed at part speed. The analyses were done for baseline rotor, devoid of any sweep, and with and without circumferential casing grooves. A detailed flow field investigation and performance comparison is presented to understand the changes in flow field at part speed. It is found that that at 100% design speed, stall margin improvement is achived by both sweep and casing grooves, but at 90% speed improvement in stall margin due to sacing groove is very minimal over and above the gain due to sweep. It is also noticed that due to reduced shock loss efficiency is higher at 90% speed than at 100% speed.

Dynamic Characteristic Simulation and Analysis of Blade Flutter Based on Finite Element

2013 ◽  
Vol 753-755 ◽  
pp. 973-976
Author(s):  
Li Da Zhu ◽  
Wen Wen Liu ◽  
Ji Jiang Wu ◽  
Shuai Xu ◽  
Peng Cheng Su
Keyword(s):  
Finite Element ◽  
Dynamic Characteristic ◽  
Optimization Design ◽  
Simulation Analysis ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Element Analysis ◽  
Turbine Engine ◽  
Blade Flutter

Blade is one of the main parts of aircraft engine. Its dynamic characteristics will produce important influence on the work efficiency and the operation reliability of the turbine engine. The paper used the theory of finite element to do modal simulation analysis on the dynamic characteristic of blade flutter, aiming at the phenomenon of serious blade vibration in the process of turbine engine running. Firstly, the paper generated a three-dimensional model by using the software UG. Then the three-dimensional model was leaded into the finite element analysis software ANSYS. Simulation analysis of the model was carried out by using the Workbench module of ANSYS software. Finally, we got the former six order natural frequencies and vibration modes of the blade. In addition, we got the blade's vibration characteristics. The results of the simulation could provide numerical basis for the blades optimization design and vibration safety inspection.

3D Numerical Investigation of Tandem Airfoils for a Core Compressor Rotor

2008 ◽  
Author(s):  
Jonathan McGlumphy ◽  
Wing-Fai Ng ◽  
Steven R. Wellborn ◽  
Severin Kempf
Keyword(s):  
Turbulent Flow ◽  
Fluid Mechanics ◽  
Numerical Investigation ◽  
Boundary Layers ◽  
Three Dimensional ◽  
Compressor Blade ◽  
Stall Margin ◽  
Compressor Rotor ◽  
Blade Geometry

The tandem airfoil has potential to do more work as a compressor blade than a single airfoil without incurring higher losses. The goal of this work is to evaluate the fluid mechanics of a tandem rotor in the rear stages of a core compressor. As such, the results are constrained to shock-free, fully turbulent flow with thick endwall boundary layers at the inlet. A high hub-to-tip ratio 3D blade geometry was developed based upon the best-case tandem airfoil configuration from a previous 2D study. The 3D tandem rotor was simulated in isolation in order to scrutinize the fluid mechanisms of the rotor, which had not previously been well documented. A geometrically similar single blade rotor was also simulated under the same conditions for a baseline comparison. The tandem rotor was found to outperform its single blade counterpart by attaining a higher work coefficient, polytropic efficiency and numerical stall margin. An examination of the tandem rotor fluid mechanics revealed that the forward blade acts in a similar manner to a conventional rotor. The aft blade is strongly dependent upon the flow it receives from the forward blade, and tends to be more three-dimensional and non-uniform than the forward blade.

Development of Hub Corner Stall and Its Influence on the Performance of Axial Compressor Blade Rows

1999 ◽  
Vol 121 (1) ◽  
pp. 67-77 ◽  
Author(s):  
C. Hah ◽  
J. Loellbach
Keyword(s):  
Numerical Solutions ◽  
Stokes Equations ◽  
Flow Direction ◽  
Three Dimensional ◽  
Suction Side ◽  
Compressor Blade ◽  
Suction Surface ◽  
Simple Diffusion ◽  
Transonic Compressor ◽  
Compressor Rotor

A detailed investigation has been performed to study hub corner stall phenomena in compressor blade rows. Three-dimensional flows in a subsonic annular compressor stator and in a transonic compressor rotor have been analyzed numerically by solving the Reynolds-averaged Navier–Stokes equations. The numerical results and the existing experimental data are interrogated to understand the mechanism of compressor hub corner stall. Both the measurements and the numerical solutions for the stator indicate that a strong twisterlike vortex is formed near the rear part of the blade suction surface. Low-momentum fluid inside the hub boundary layer is transported toward the suction side of the blade by this vortex. On the blade suction surface near the hub, this vortex forces fluid to move against the main flow direction and a limiting stream surface is formed near the hub. The formation of this vortex is the main mechanism of hub corner stall. When the aerodynamic loading is increased, the vortex initiates further upstream, which results in a larger corner stall region. For the transonic compressor rotor studied in this paper, the numerical solution indicates that a mild hub corner stall exists at 100 percent rotor speed. The hub corner stall, however, disappears at the reduced blade loading, which occurs at 60 percent rotor design speed. The present study demonstrates that hub corner stall is caused by a three-dimensional vortex system and that it does not seem to be correlated with a simple diffusion factor for the blade row.

scholarly journals Modeling and Verification of Creep Strain and Exhaustion in a Welded Steam Mixer

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
Stefan Holmström ◽  
Juhani Rantala ◽  
Anssi Laukkanen ◽  
Kari Kolari ◽  
Heikki Keinänen ◽  
...  
Keyword(s):  
Creep Strain ◽  
Three Dimensional ◽  
Creep Damage ◽  
Tertiary Creep ◽  
Dimensional Structure ◽  
Rigid Plastic ◽  
Element Analysis ◽  
Filtering Technique ◽  
Long Term Behavior ◽  
Creep Regime

Structures operating in the creep regime will consume their creep life at a greater rate in locations where the stress state is aggravated by triaxiality constraints. Many structures, such as the welded steam mixer studied here, also have multiple material zones differing in microstructure and material properties. The three-dimensional structure as such, in addition to interacting material zones, is a great challenge for finite element analysis (FEA), even to accurately pinpoint the critical locations where damage will be found. The studied steam mixer, made of 10CrMo 9-10 steel (P22), has after 100,000 h of service developed severe creep damage in several saddle point positions adjacent to nozzle welds. FE-simulation of long term behavior of this structure has been performed taking developing triaxiality constraints, material zones, and primary to tertiary creep regimes into account. The creep strain rate formulation is based on the logistic creep strain prediction model implemented to ABAQUS, including primary, secondary, and tertiary creep. The results are presented using a filtering technique utilizing the formulation of rigid plastic deformation for describing and quantifying the developing “creep exhaustion.”

Experimental Study of the Flow Field Within a Transonic Axial Compressor Rotor by Laser Velocimetry and Comparison With Through-Flow Calculations

1978 ◽  
Vol 100 (2) ◽  
pp. 279-286 ◽  
Author(s):  
R. J. Dunker ◽  
P. E. Strinning ◽  
H. B. Weyer
Keyword(s):  
Flow Field ◽  
Pressure Ratio ◽  
Analytical Data ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Compressor Rotor ◽  
Through Flow ◽  
Equivalent Mass ◽  
Transonic Axial Compressor ◽  
Design Speed

The flow field ahead, within, and behind the rotor of a transonic axial compressor designed for a total pressure ratio of 1.51 at a relative tip Mach number of 1.4 has been studied in detail using an advanced laser velocimeter. The tests were carried out at 70 and 100 percent design speed (20,260 rpm) and equivalent mass flows corresponding to the point of maximum isentropic efficiency. The tests yielded quite complete data on the span- and gap-wise velocity profiles, on the three-dimensional shock waves in and outside of the rotor blade channels, and on the blade wakes. Some of the experimental results will be submitted, discussed, and compared to corresponding analytical data of a through-flow calculation. The comparison reveals considerable discrepancies inside the blade row between the two-dimensional calculation and the experiments primarily due to the loss and deviation correlations used, as well as to the distribution of losses and flow angles inside the blade channels.

Aerodynamic Design and Analysis of a Multistage Vaneless Counter-Rotating Turbine

2014 ◽  
Author(s):  
Wei Zhao ◽  
Bing Wu ◽  
Jianzhong Xu
Keyword(s):  
Power Output ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Weight Ratio ◽  
Total Efficiency ◽  
Aerodynamic Design ◽  
Element Analysis ◽  
Turbine Engine ◽  
Viscous Losses ◽  
Axial Acceleration

Multistage vaneless counter-rotating turbines eliminate vanes between rotors, which reduces the weight of the turbine pronouncedly and avoids viscous losses associated with vanes. As a result, a gas turbine engine employing such a turbine would have greater thrust to weight ratio and smaller specific fuel consumption. This paper presents aerodynamic design and analysis for a multistage vaneless counter-rotating turbine, named as a 4*1/2 turbine, which consists of a rotating frame and four rotors without any vanes. The first rotor and the third rotor drive a single-shaft compressor with a pressure ratio of 11.8, and the second rotor and the forth rotor deliver a total shaft power of around 2MW. Stage loading and flow axial acceleration in blades and ducts are selected to provide sufficient inlet swirl for downstream vaneless rotor to produce required power output with acceptable performance. The stage work coefficients of each rotor are 0.95, 2.9, 1.4 and 1.0, respectively. Non-uniform radial circulation distributions and tapered blades are also used to maximize the turbine power output. Centrifugal forces in the outer rotor of the turbine are captured by carrying out a finite element analysis to validate the aerodynamic design results. Three dimensional viscous numerical results show that an adiabatic total-to-total efficiency of 91.5% with a pressure ratio of 9.8 at design condition is obtained and achieves the initial design objective very well. Entropy creation associated with the tip leakage and secondary flow in each rotor is also illustrated for understanding the origins and effects of losses in such turbines. Pressure ratios and efficiency at speed combinations of the 80% to 100% design speeds of the inner and outer rotors are discussed to reveal the turbine characteristics at off-design conditions.

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