An improved Jacobian-Torsor model for statistical variation solution in aero-engine rotors assembly

2020 ◽  
pp. 095440542095876
Author(s):  
Siyi Ding ◽  
Xiaohu Zheng ◽  
Jinsong Bao ◽  
Jie Zhang
Keyword(s):  
Three Dimensional ◽  
Statistical Variation ◽  
Variation Propagation ◽  
Aero Engine ◽  
Core Components ◽  
Key Issues ◽  
Assembly Technology ◽  
Parts Manufacturing ◽  
Rotor Assembly ◽  
Engine Rotors

Rotor assembly is one of the core components of aero-engine, which basically consists of multistage revolving components. With the influence of parts’ manufacturing errors and practical assembly technology, assembly variations are unavoidable which will cause insecurity and unreliable of the whole engine. Statistical variation solution is a feasible means to analyze assembly precision. When using the three-dimensional variation analysis in rotor assembly, two key issues cannot be well solved, which involve the variation expression (the over-positioning problem of multiple datums) and the variation propagation (revolving characteristic of the rotors). To overcome the deficiency, extended Jacobian matrix and updated torsor equation were derived and unified, which eventually resulted in the improved Jacobian-Torsor model. This model can both provide rotation regulating mechanism by introducing the revolution joint, and characterize the interaction between essential mating features. Multistage rotational optimization of four-stage aero-engine rotors assembly has been performed to demonstrate this solution in statistical way. Results showed that the proposed model was applicable and conducive to precision prediction and analysis in design preliminary stage.

scholarly journals A Probabilistic Approach for Three-Dimensional Variation Analysis in Aero-engine Rotors Assembly

2021 ◽  
Author(s):  
Siyi Ding ◽  
Yuhang He ◽  
Xiaohu Zheng
Keyword(s):  
Design Theory ◽  
Probabilistic Approach ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Variation Analysis ◽  
Variation Propagation ◽  
Aero Engine ◽  
Dimensional Variation ◽  
Similar Accuracy ◽  
Rotor Assembly

AbstractRotor assembly is a core tache in the whole process of aero-engine manufacturing. Preventing out-of-tolerance of concentricity is one of the primary tasks. Conventional assembly approaches are based on a manual test with the dial indicator, depending on experience appraises, which lack systematic and quantitative precision design theory. As a result, two issues need to be solved: the modeling problem of complicated geometric variations in three-dimensions, as well as the abnormal distribution of ubiquitous actual deviations. This work attempts to propose a novel probabilistic approach for three-dimensional variation analysis in rotor assembly. Based on rotor’s revolving characteristics and multistage stacking process, Jacobian–Torsor model is adopted to establish the variation propagation, and Pearson distribution family is used to derive the probability density function, which can quickly determine the variation distribution pattern and efficiently perform statistical variation analysis. A real case of mechanical assemblies consisting of revolving axisymmetric components is concerned. The results show that the suggested method has a similar accuracy, but much higher efficiency than conventional methods. Calculations agree with the experimentations, and the probability distribution type of the part’s variation has an appreciable impact on the final assembly precision.

Robust Design of Aero-Engine Assembly Using Taguchi Method Based on Jacobian-Torsor Model

2019 ◽  
Author(s):  
Siyi Ding ◽  
Xiaohu Zheng ◽  
Jinsong Bao ◽  
Jie Zhang
Keyword(s):  
Robust Design ◽  
Optimization Method ◽  
Design Stage ◽  
Original Design ◽  
Traditional Methods ◽  
Geometrical Errors ◽  
Statistical Variation ◽  
Variation Propagation ◽  
Aero Engine ◽  
The Rich

Abstract Aero-engine assembly is the core tache in the whole process of aero-engine manufacturing. Assembly variations are unavoidable due to parts’ geometrical errors. Statistical variation analysis is an effective method for robust design that can quantitatively predict product quality in the original design stage. However, traditional methods focus on the modeling of plane dimension chain and extremum analysis, which is difficult to comprehensively consider the rich geometrical errors and their relationship to each other; meanwhile, the precision prediction is too conservative to reduce the parts’ rework frequency and adjusting difficulty; in addition, traditional methods overemphasize the promotion of parts’ machining precision, and ignore the means of overall stack optimization. To overcome these problems, firstly, Jacobian-Torsor (J-T) model is used to build the variation propagation, which is well suited to a complex assembly that contains large numbers of joints and geometric tolerances; secondly, combining with Monte Carlo simulation and J-T statistical contribution solution, the percentage contribution of each part could be solved; Finally, Taguchi multi-objective optimization method is adopted for robust design of the whole system. A case study on an entire aero-engine assembly is presented to illustrate the proposed method and the results show that this new method can effectively evaluate the assembly performance and determine the optimal assembly plan, which has strong practical guiding significance.

Improvement of Variation Propagation Control in Mechanical Assembly Using Adjustment Assembly Technique

2017 ◽  
Vol 870 ◽  
pp. 459-464 ◽  
Author(s):  
Chuan Zhi Sun ◽  
Lei Wang ◽  
Jiu Bin Tan ◽  
Bo Zhao ◽  
Guo Liang Jin ◽  
...  
Keyword(s):  
Assembly Model ◽  
Mechanical Assembly ◽  
Assembly Quality ◽  
Cumulative Error ◽  
Assembly Method ◽  
Variation Propagation ◽  
Rotationally Symmetric ◽  
Aero Engine ◽  
Assembly Technique ◽  
Engine Components

This paper aims to provide an assembly method to improve mechanical assembly quality. In order to improve the variation propagation control in rotationally symmetric cylindrical components assembly, the eccentric and tilt errors of a single rotor stage were taken into account using a connective assembly model and the eccentric deviation in a mechanical assembly was minimized by properly selecting component orientations. Compared to the minimum cumulative error, the maximum cumulative error was reduced by 71 percent, and the average cumulative error was reduced by 57 percent in the assembly of three components. This article provides an assembly method through variation propagation control in rotationally symmetric cylindrical components assembly. The method could be extended to rotationally symmetric cylindrical components assembly, for example in the assembly of aero-engine components.

A High Fidelity Quality Assessment of High Pressure Turbine Blades Using Surface Curvature and Gradient-Based Adjoint

2018 ◽  
Author(s):  
Akhil Mulloth ◽  
Gabriel Banks ◽  
Giulio Zamboni ◽  
Simon Bather
Keyword(s):  
Quality Assessment ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Surface Curvature ◽  
Assessment Process ◽  
Screening Process ◽  
Profile Tolerance ◽  
Gradient Based ◽  
Parts Manufacturing ◽  
The Impact

Gas turbine performance is highly dependent on the quality of the manufactured parts. Manufacturing variations in the parts can significantly alter the performance, especially efficiency and thus SFC. The legacy process is to accept variations within predefined profile tolerance limits and a few other qualitative parameters, mostly at a few, key two-dimensional aerofoil sections. With the widespread use of White light scans and other similar three-dimensional scans, this has improved to include the three-dimensional profile. The future however may lie with performance based quality assessment of manufactured parts, combined with quantitative surface quality assessment to implement an intelligent screening process for the parts. The adjoint method, typically used for shape optimization is adapted to provide a prediction of the impact on performance due to manufacturing variations. The work presented outlines a three stage quality assessment process for manufactured parts, involving three-dimensional profile tolerance based screening, followed by a surface curvature based screening and finally an Adjoint based performance prediction.

Forced Response Variation of Aerodynamically and Structurally Mistuned Turbo-Machinery Rotors

2006 ◽  
Author(s):  
I. Sladojevic´ ◽  
E. P. Petrov ◽  
M. Imregun ◽  
A. I. Sayma
Keyword(s):  
Three Dimensional ◽  
Forced Response ◽  
Navier Stokes ◽  
Fe Model ◽  
Frequency Shifts ◽  
Aero Engine ◽  
Different Types ◽  
Aerodynamic Parameters ◽  
Reynolds Averaged Navier Stokes ◽  
Response Variation

The paper presents the results of a study looking into changes in the forced response levels of bladed disc assemblies subject to both structural and aerodynamic mistuning. A whole annulus FE model, representative of a civil aero-engine fan with 26 blades was used in the calculations. The forced response of all blades of 1000 random mistuned patterns was calculated. The aerodynamic parameters, frequency shifts and damping, were calculated using a three-dimensional Reynolds-averaged Navier-Stokes aero-elasticity code. They were randomly varied for each mistuning pattern, with the assumption that the system would remain stable, i.e. flutter would not occur due to aerodynamic mistuning. The results show the variation of the forced response with different types of mistuning, with structural mistuning only, with aerodynamic mistuning only and with both structural and aerodynamic mistuning.

Quantifying Design Feasibility Using Probabilistic Feasibility Analysis

1991 ◽  
Author(s):  
R. J. Eggert
Keyword(s):  
Design Space ◽  
Mechanical Design ◽  
Three Dimensional ◽  
Feasibility Analysis ◽  
Manufacturing Processes ◽  
Moment Matching ◽  
Probabilistic Constraint ◽  
Constraint Equations ◽  
Design Specifications ◽  
Variation Propagation

Abstract Engineered products are designed for manufacture using nominal values and tolerances. As such, finished products will more or less satisfy design specifications depending on the actual materials and manufacturing processes used. Design feasibility, therefore, depends on how these variations impact specified constraints. Probabilistic feasibility analysis can be used to extend conventional feasibility analysis. By using moment matching and simulation, the probability of points occurring in the design space can be evaluated. The resulting values establish the limits of feasibility and the amount of feasibility in between. The nature of variation in mechanical design is introduced along with concepts of variation propagation in functions of random variables. Moment matching methods are applied to illustrative cases consisting of deterministic and probabilistic constraint equations, resulting in three dimensional feasibility mappings of each design space.

Three-dimensional organization of the flow structure in a non-reactive model aero engine lean burn injection system

2014 ◽  
Vol 52 ◽  
pp. 164-173 ◽  
Author(s):  
Giuseppe Ceglia ◽  
Stefano Discetti ◽  
Andrea Ianiro ◽  
Dirk Michaelis ◽  
Tommaso Astarita ◽  
...  
Keyword(s):  
Flow Structure ◽  
Three Dimensional ◽  
Injection System ◽  
Lean Burn ◽  
Aero Engine
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