Adjoint-Based Optimization of a Modern Jet-Engine Fan Blade

2020 ◽  
Author(s):  
Andrea Giugno ◽  
Shahrokh Shahpar ◽  
Alberto Traverso
Keyword(s):  
Design Space ◽  
Characteristic Curve ◽  
Free Form ◽  
Design Parameters ◽  
Jet Engine ◽  
Discrete Adjoint ◽  
Active Design ◽  
Fan Blade ◽  
Adjoint Gradient ◽  
Real Test

Abstract A Multi-point Approximation Method (MAM) coupled with adjoint is presented to increase the efficiency of a modern jet-engine fan blade. The study performed makes use of Rolls-Royce in-house suite of codes and its discrete adjoint capability. The adjoint gradient is used along with MAM to create a Design Of Experiment to enhance the optimization process. A generalized Free-Form Deformation (FFD) technique is used to parametrize the geometry, creating a design space of 180 parameters. The resulting optimum blade at design conditions is then evaluated at off-design conditions to produce the characteristic curve, which is compared with real test data. Finally, a preliminary Active Design Subspace (ADS) representing the fan efficiency is created to evaluate the robustness of the objective function in respect to the most significant design parameters. The ADS allows to collapse a large design space of the order of hundreds parameters to the few most important variables, measuring their contribution. This map is valuable in many respects to the fan designers and manufacture engineers to identify any ridges where the performance may deteriorate rapidly, hence a more robust part of the design space can easily be visualized and identified.

scholarly journals Computational Design Optimization for S-Ducts

Designs ◽  
2018 ◽  
Vol 2 (4) ◽  
pp. 36 ◽  
Author(s):  
Alessio D’Ambros ◽  
Timoleon Kipouros ◽  
Pavlos Zachos ◽  
Mark Savill ◽  
Ernesto Benini
Keyword(s):  
Design Space ◽  
Computational Design ◽  
Free Form ◽  
Design Parameters ◽  
Heuristic Optimization ◽  
Objective Functions ◽  
Pressure Losses ◽  
Optimization Study ◽  
Free Form Deformation ◽  
Computational Fluid Dynamics Cfd

In this work, we investigate the computational design of a typical S-Duct that is found in the literature. We model the design problem as a shape optimization study. The design parameters describe the 3D geometrical changes to the shape of the S-Duct and we assess the improvements to the aerodynamic behavior by considering two objective functions: the pressure losses and the swirl. The geometry management is controlled with the Free-Form Deformation (FFD) technique, the analysis of the flow is performed using steady-state computational fluid dynamics (CFD), and the exploration of the design space is achieved using the heuristic optimization algorithm Tabu Search (MOTS). The results reveal potential improvements by 14% with respect to the pressure losses and by 71% with respect to the swirl of the flow. These findings exceed by a large margin the optimality level that was achieved by other approaches in the literature. Further investigation of a range of optimum geometries is performed and reported with a detailed discussion.

Modeling Surface Variation and Assessment of its Impact on Aerodynamic Performance in Turbomachinery Applications

2017 ◽  
Author(s):  
Saurya Ranjan Ray ◽  
Ravikanth Avancha ◽  
Sriram Shankaran ◽  
Lyle Dailey
Keyword(s):  
Product Life Cycle ◽  
Design Space ◽  
Correlation Coefficients ◽  
Local Effect ◽  
Free Form ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Critical Dimensions ◽  
Measuring Machine ◽  
The Impact

Analyzing the impact of manufacturing variability on the performance of turbomachinery components supports two critical dimensions in the product life cycle. It provides a technological process to decide on the criterion of acceptability of the deviated manufactured component based on the performance assessment and secondly, provides sensitivity of the geometrical variation to the component performance to build a robust design space. Currently, non-deterministic methods based on probability distribution function of the design parameters are used to assess the impact of variability, and the output is presented as a set of correlation coefficients linking the geometrical parameters to the component performance. Though these methods provide adequate information on the robustness of the design space, the amount of computational requirement and lack of consideration of the local effect of geometry modification on the performance pose challenges. In the current work, the method presented is based on a variant of radial basis functions to construct the deviated manufactured geometry of the turbine rear frame (TRF) of a modern gas turbine engine for aerodynamic assessment. The approach is used to accurately and rapidly construct a 3D deviation map from a set of discrete measured data using a co-ordinate measuring machine (CMM). Additionally, the developed approach is used as a method of applying free-form deformation in the critical localities on the aerodynamic surface identified using the sensitivity information from an adjoint analysis to re-design the baseline geometry. Aerodynamic analysis is conducted to understand the nature of geometry change due to the manufacturing variation and explain the mechanism of performance change.

scholarly journals Evaluation of Static Mapping for Dynamic Space-Shared Multi-task Processing on FPGAs

2021 ◽  
Author(s):  
Umar Ibrahim Minhas ◽  
Roger Woods ◽  
Georgios Karakonstantis
Keyword(s):  
High Performance ◽  
Design Space Exploration ◽  
Design Space ◽  
System Throughput ◽  
Design Parameters ◽  
Temporal Constraints ◽  
Shared Resources ◽  
Task Processing ◽  
High Level ◽  
Performance Computing

AbstractWhilst FPGAs have been used in cloud ecosystems, it is still extremely challenging to achieve high compute density when mapping heterogeneous multi-tasks on shared resources at runtime. This work addresses this by treating the FPGA resource as a service and employing multi-task processing at the high level, design space exploration and static off-line partitioning in order to allow more efficient mapping of heterogeneous tasks onto the FPGA. In addition, a new, comprehensive runtime functional simulator is used to evaluate the effect of various spatial and temporal constraints on both the existing and new approaches when varying system design parameters. A comprehensive suite of real high performance computing tasks was implemented on a Nallatech 385 FPGA card and show that our approach can provide on average 2.9 × and 2.3 × higher system throughput for compute and mixed intensity tasks, while 0.2 × lower for memory intensive tasks due to external memory access latency and bandwidth limitations. The work has been extended by introducing a novel scheduling scheme to enhance temporal utilization of resources when using the proposed approach. Additional results for large queues of mixed intensity tasks (compute and memory) show that the proposed partitioning and scheduling approach can provide higher than 3 × system speedup over previous schemes.

Adaptive Geometry Representation of Turbine Vane Frames for Use in Optimization

2021 ◽  
Author(s):  
Sebastian F. Riebl ◽  
Christian Wakelam ◽  
Reinhard Niehuis
Keyword(s):  
Design Space ◽  
Cfd Simulation ◽  
A Priori ◽  
Three Dimensional ◽  
Optimization Method ◽  
Three Dimensions ◽  
Design Parameters ◽  
Adjustment Process ◽  
Turbine Vane ◽  
Integrated Concept

Abstract Turbine Vane Frames (TVF) are a way to realize more compact jet engine designs. Located between the high pressure turbine (HPT) and the low pressure turbine (LPT), they fulfill structural and aerodynamic tasks. When used as an integrated concept with splitters located between the structural load-bearing vanes, the TVF configuration contains more than one type of airfoil with sometimes pronouncedly different properties. This system of multidisciplinary demands and mixed blading poses an interesting opportunity for optimization. Within the scope of the present work, a full geometric parameterization of a TVF with splitters is presented. The parameterization is chosen as to minimize the number of parameters required to automatically and flexibly represent all blade types involved in a TVF row in all three dimensions. Typical blade design parameters are linked to the fourth order Bézier-curve controlled camber line-thickness parameterization. Based on conventional design rules, a procedure is presented, which sets the parameters within their permissible ranges according to the imposed constraints, using a proprietary developed code. The presented workflow relies on subsequent three dimensional geometry generation by transfer of the proposed parameter set to a commercially available CAD package. The interdependencies of parameters are discussed and their respective significance for the adjustment process is detailed. Furthermore, the capability of the chosen parameterization and adjustment process to rebuild an exemplary reference TVF geometry is demonstrated. The results are verified by comparing not only geometrical profile data, but also validated CFD simulation results between the rebuilt and original geometries. Measures taken to ensure the robustness of the method are highlighted and evaluated by exploring extremes in the permissible design space. Finally, the embedding of the proposed method within the framework of an automated, gradient free numerical optimization is discussed. Herein, implications of the proposed method on response surface modeling in combination with the optimization method are highlighted. The method promises to be an option for improvement of optimization efficiency in gradient free optimization of interdependent blade geometries, by a-priori excluding unsuitable blade combinations, yet keeping restrictions to the design space as limited as possible.

Nonrelative sliding of spiral bevel gear mechanism based on active design of meshing line

2018 ◽  
Vol 233 (3) ◽  
pp. 1055-1067 ◽  
Author(s):  
Zhen Chen ◽  
Ming Zeng
Keyword(s):  
Design Method ◽  
Bevel Gear ◽  
Transmission Mechanism ◽  
Tooth Surface ◽  
Design Parameters ◽  
Spiral Bevel Gear ◽  
Bevel Gears ◽  
Gear Mechanism ◽  
Active Design ◽  
Spiral Bevel

In this paper, an active design method of meshing line for a spiral bevel gear mechanism with nonrelative sliding is presented. First, the general meshing line equations for a nonrelative sliding transmission mechanism between two orthogonal axes are proposed based on the active design parameters. Then, parametric equations for contact curves on the drive and driven spiral bevel gears are deduced by coordinate transformation of the meshing line equations. Further to this, parametric equations for the tooth surface of each bevel gear are derived according to the conical spiral motion of a generatrix circle along the calculated contact curves. Finally, a set of numerical examples is presented based on two types of motion equation of the meshing points. Material prototypes are fabricated and experimentally tested to validate the kinematic performance of the functionally designed spiral bevel gear set.

Ball Drive Configurations and Kinematics for Holonomic Ground Mobility

2017 ◽  
Author(s):  
Biruk A. Gebre ◽  
Kishore Pochiraju
Keyword(s):  
Design Space ◽  
Kinematic Model ◽  
Design Parameters ◽  
Actuation Force ◽  
Confined Spaces ◽  
Naming Convention ◽  
Trade Offs ◽  
Vehicle Velocity ◽  
And Performance ◽  
Selection Of

Holonomic motion is desired for mobile ground robots and vehicles as it provides omnidirectional maneuvering capabilities, which can simplify the task of navigating around obstacles in confined spaces and unstructured environments. Mobility platforms that utilize spherical wheels are gaining popularity and interest due to the agile maneuvering and ground traversal capabilities they enable for mobility platforms. Ball-driven mobility platforms have a rich design space as various design parameters are available that can modify the physical and performance characteristics of the platforms. Various configurations for ball-driven mobility platforms are presented along with a generalized kinematic model that can be used for calculating motor velocities for a desired vehicle velocity. A naming convention is also presented in the paper for differentiating between configurations used for ball-driven mobility platforms. Metrics such as platform footprint, platform stability, and actuation force and efficiency are used to compare the configurations and to highlight some of the trade-offs associated with the selection of a configuration. Promising configurations are highlighted based on the metrics selected for the comparisons.

Design Manifolds Capture the Intrinsic Complexity and Dimension of Design Spaces

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Wei Chen ◽  
Mark Fuge ◽  
Jonah Chazan
Keyword(s):  
Geometric Modeling ◽  
Design Space ◽  
Dimensional Space ◽  
Consumer Preference ◽  
Shape Reconstruction ◽  
Pairwise Distance ◽  
Design Parameters ◽  
Improve Design ◽  
Intrinsic Complexity ◽  
Semantic Attributes

This paper shows how to measure the intrinsic complexity and dimensionality of a design space. It assumes that high-dimensional design parameters actually lie in a much lower-dimensional space that represents semantic attributes—a design manifold. Past work has shown how to embed designs using techniques like autoencoders; in contrast, the method proposed in this paper first captures the inherent properties of a design space and then chooses appropriate embeddings based on the captured properties. We demonstrate this with both synthetic shapes of controllable complexity (using a generalization of the ellipse called the superformula) and real-world designs (glassware and airfoils). We evaluate multiple embeddings by measuring shape reconstruction error, pairwise distance preservation, and captured semantic attributes. By generating fundamental knowledge about the inherent complexity of a design space and how designs differ from one another, our approach allows us to improve design optimization, consumer preference learning, geometric modeling, and other design applications that rely on navigating complex design spaces. Ultimately, this deepens our understanding of design complexity in general.

J0110103 A dynamic behavior analysis of jet-engine fan blade under impact loading

2015 ◽  
Vol 2015 (0) ◽  
pp. _J0110103--_J0110103-
Author(s):  
Bidhar Kumar SUJIT ◽  
Yoshinori SHIIHARA ◽  
Nobuhiro YOSHIKAWA ◽  
Hiroshi KUROKI ◽  
Masahiro HOJO
Keyword(s):  
Behavior Analysis ◽  
Dynamic Behavior ◽  
Impact Loading ◽  
Jet Engine ◽  
Fan Blade

Bird strike analysis of jet engine fan blade

2014 ◽  
Author(s):  
Narender Lakshman ◽  
Ratnesh Raj ◽  
Yagnavalkya Mukkamala
Keyword(s):  
Bird Strike ◽  
Jet Engine ◽  
Fan Blade

scholarly journals Design Space of Flexible Multigigabit LDPC Decoders

VLSI Design ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Philipp Schläfer ◽  
Christian Weis ◽  
Norbert Wehn ◽  
Matthias Alles
Keyword(s):  
Design Space ◽  
State Of The Art ◽  
Cmos Technology ◽  
Systematic Investigation ◽  
Design Parameters ◽  
Ldpc Decoder ◽  
The Past ◽  
Ieee 802.11Ad ◽  
Decoder Design ◽  
First Time

Multigigabit LDPC decoders are demanded by standards like IEEE 802.15.3c and IEEE 802.11ad. To achieve the high throughput while supporting the needed flexibility, sophisticated architectures are mandatory. This paper comprehensively presents the design space for flexible multigigabit LDPC applications for the first time. The influence of various design parameters on the hardware is investigated in depth. Two new decoder architectures in a 65 nm CMOS technology are presented to further explore the design space. In the past, the memory domination was the bottleneck for throughputs of up to 1 Gbit/s. Our systematic investigation of column- versus row-based partially parallel decoders shows that this is no more a bottleneck for multigigabit architectures. The evolutionary progress in flexible multigigabit LDPC decoder design is highlighted in an extensive comparison of state-of-the-art decoders.

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