A Family of Surface Velocity Distributions for Axial Compressor Blading and Their Theoretical Performance

1976 ◽  
Vol 98 (2) ◽  
pp. 229-238 ◽  
Author(s):  
G. J. Walker
Keyword(s):  
High Performance ◽  
Axial Compressor ◽  
Compressor Blade ◽  
Surface Velocity ◽  
Design Parameters ◽  
Suction Surface ◽  
Wide Range ◽  
Using Data ◽  
High Level ◽  
Theoretical Performance

The influence of free stream disturbances on transition is discussed and it is noted that significant regions of laminar flow may exist on axial turbomachine blades despite the high level of disturbance to which they are subjected. A family of surface velocity distributions giving unseparated flow on the suction surface of an axial compressor blade is derived using data from detailed boundary layer measurements on the blading of a single-stage machine. The distributions are broadly similar to those adopted by Wortmann in designing high performance isolated aerofoil sections for operation at much higher Reynolds numbers. The theoretical performance of blades having the specified surface velocity distributions is computed for a wide range of conditions, and the effects of varying Reynolds number and other design parameters are analyzed. The results suggest the possibility of obtaining useful improvements in performance over that of conventional compressor blade sections. The computed performance values show an almost unique relation between the blade losses and the suction surface diffusion ratio. However the correlation of losses with the equivalent diffusion ratio is found to break down at high values of the latter parameter.

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.

scholarly journals Optimization Aspects of an Ejector Type Hypersonic Thrust Nozzle

1992 ◽  
Author(s):  
G. Trittler ◽  
E. Eckert ◽  
M. Göing
Keyword(s):  
High Performance ◽  
Exhaust System ◽  
Vital Role ◽  
Calculation Model ◽  
Nozzle Geometry ◽  
Design Parameters ◽  
Axial Thrust ◽  
Thrust Coefficient ◽  
Wide Range ◽  
Low Performance

Hypersonic aircraft projects are highly dependant on efficient propulsion systems. High performance and integration within the airframe play a vital role in the overall concept. Particular attention must be paid to the exhaust system that is submitted to a wide range of operational requirements. An optimization of the nozzle geometry for high flight Mach numbers will lead to a low performance at the transonic flight regime. The additional use of secondary ejector air flow at transonic speeds is one option to improve the thrust behaviour of the nozzle. In the presented paper performance data of single expansion ramp ejector type nozzles are predicted using a calculation model based on a method-of-characteristics algorithm. For optimization purposes the effects of various design parameters on axial thrust coefficient and thrust vector angle are discussed. The geometric parameters investigated are the length of the lower nozzle wall and its deflection angle as well as the ejector slot location and its cross-section.

Sweep in a Transonic Fan Rotor: Part 1 — 3D Geometry Package

1998 ◽  
Author(s):  
Hazem F. Abdelhamid ◽  
Raymond P. Shreeve
Keyword(s):  
Axial Compressor ◽  
Compressor Blade ◽  
Design Parameters ◽  
Control Points ◽  
Manufacturing Optimization ◽  
3D Geometry ◽  
Blade Shape ◽  
Two Parameters ◽  
Transonic Fan ◽  
Blade Element

A geometry package was developed which uses six Bezier surfaces to describe an axial compressor blade. The blade is defined by 32 control points and two parameters, which determine the leading and trailing edge extensions. The package was used to represent a reference transonic fan rotor to within machining tolerances, and then to introduce forward and backward sweep holding blade-element design parameters fixed. Blade lean and point geometry manipulations were also demonstrated. All geometries produced by the package are machinable without approximation. The Bezier-surface representation was chosen in order to minimize the number of control points required to specify the blade shape and eventually enable aero-structural-manufacturing optimization.

CFD-based blade shape optimization of MGT-70(3)axial flow compressor

2019 ◽  
Vol 30 (6) ◽  
pp. 3307-3321 ◽  
Author(s):  
Mohammad Reza Pakatchian ◽  
Hossein Saeidi ◽  
Alireza Ziamolki
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Shape Optimization ◽  
Fluid Dynamic ◽  
Axial Compressor ◽  
Axial Flow ◽  
Design Parameters ◽  
Content Type ◽  
Wide Range ◽  
Artificial Neural

Purpose This study aims at enhancing the performance of a 16-stage axial compressor and improving the operating stability. The adopted approaches for upgrading the compressor are artificial neural network, optimization algorithms and computational fluid dynamics. Design/methodology/approach The process starts with developing several data sets for certain 2D sections by means of training several artificial neural networks (ANNs) as surrogate models. Afterward, the trained ANNs are applied to the 3D shape optimization along with parametrization of the blade stacking line. Specifying the significant design parameters, a wide range of geometrical variations are considered by implementation of appropriate number of design variables. The optimized shapes are analyzed by applying computational fluid dynamic to obtain the best geometry. Findings 3D optimal results show improvements, especially in the case of decreasing or elimination of near walls corner separations. In addition, in comparison with the base geometry, numerical optimization shows an increase of 1.15 per cent in total isentropic efficiency in the first four stages, which results in 0.6 per cent improvement for the whole compressor, even while keeping the rest of the stages unchanged. To evaluate the numerical results, experimental data are compared with obtained data from simulation. Based on the results, the highest absolute relative deviation between experimental and numerical static pressure is approximately 7.5 per cent. Originality/value The blades geometry of an axial compressor used in a heavy-duty gas turbine is optimized by applying artificial neural network, and the results are compared with the base geometry numerically and experimentally.

Extremely Light Weight Rheocast Components for Automotive Space Frame

2012 ◽  
Vol 192-193 ◽  
pp. 545-550 ◽  
Author(s):  
Mario Rosso ◽  
Ildiko Peter ◽  
Gianluigi Chiarmetta ◽  
Ivano Gattelli
Keyword(s):  
High Performance ◽  
Mechanical Tests ◽  
Standard Samples ◽  
Fe Content ◽  
Wide Range ◽  
Automotive Parts ◽  
Fracture Surface Analysis ◽  
High Level ◽  
Non Destructive ◽  
Very High

This paper presents an analysis of a new rheocasting process suitable for the manufacturing of high performance automotive parts. The process is able for the realization of components using Al alloys. An important aspect is related to the possibility to obtain quite wide range of thicknesses, starting from 2.5 mm. The used alloy is the well known A356, with low Fe content, maximum 0.08 wt%. T6 heat treatments has been performed, while the soundness of the parts has been certified by non destructive tests. These parts are produced to be mounted on a top level and famous sport car. Non standard samples for mechanical tests have been machined directly from the components. Following the mechanical tests fracture surface analysis has been carried out by SEM to observe some morphological details and to evaluate the influence of the process and of the alloy conditions on the fracture behaviour. On the polished transverse sections of the samples morphological analysis has been performed. The obtained results shown high level of mechanical strength for all series of components. The reliability of the process is very high at a convenient level of manufacturing rate. The weldability of the parts has been demonstrated.

scholarly journals Observations of Wake-Induced Transition on an Axial Compressor Blade

1995 ◽  
Author(s):  
W. J. Solomon ◽  
G. J. Walker
Keyword(s):  
Reynolds Number ◽  
Axial Compressor ◽  
Reynolds Numbers ◽  
Compressor Blade ◽  
Transitional Flow ◽  
Suction Surface ◽  
Time Space ◽  
Contour Plots ◽  
Turbine Airfoils ◽  
Hot Film

A closely-spaced array of hot-film gages fully covering both suction and pressure surfaces on the outlet stator of a 1.5-stage axial compressor was used to obtain dynamic measurements of wall shear stress. Observations were made over a range of Reynolds numbers at an incidence close to the design value. Various methods of presnting the data, including time-space contour plots of ensemble-average intermittency from the film gages are analyzed: related problems of interpretation are discussed. Extensive regions of laminar flow were identified on the suction surface: at the highest Reynolds number, small laminar patches were still evident at 85% chord and transitional flow covered up to 70% of suction surface length. The influence of passing rotor wakes on transition varied markedly with Reynolds number. The behavior of wake-induced transitional strips on the suction and pressure surfaces of the compressor blade differed significantly; their propagation characteristics also varied in some respects from those observed on turbine airfoils.

scholarly journals An Investigation on Phenolic and Antioxidant Capacity of Under-utilized Food Legumes Consumed in China

Foods ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 438
Author(s):  
Yaqian Zhang ◽  
Maninder Meenu ◽  
Hansong Yu ◽  
Baojun Xu
Keyword(s):  
Antioxidant Capacity ◽  
High Performance ◽  
Total Phenolic ◽  
Velvet Bean ◽  
Local Society ◽  
Food Legumes ◽  
Wide Range ◽  
Major Producer ◽  
Phytochemical Profile ◽  
High Level

China is a major producer of various kinds of food legumes. Some of the under-utilized food legumes are consumed by the local society from different areas in China. The antioxidant capacity and phytochemical profile of these under-utilized food legumes haven’t been investigated until now. In this study, colorimetric and high-performance liquid chromatography was employed to explore the antioxidant capacity and phytochemical profile of 21 under-utilized food legumes. Different legumes under investigation exhibit a wide range of variations in their total phenolic content (TPC), total flavonoids content (TFC) and condensed tannins content (CTC). Among all the legume samples, the velvet bean from Hechi, Guangxi exhibited the highest antioxidant capacity while the white flat bean from Shangrao, Shanxi presented the least antioxidant capacity. Gallic acid was observed to be a major phenolic acid and its content in the velvet bean was significantly higher compared to the other legume samples explored in this study. The composition of flavonoids was different among all the legumes. Kaempferol was observed to be the most predominant flavonoid. The findings of this study will be beneficial for plant breeders, food scientists and consumers for the better selection of germplasm with a high level of phytochemicals that in turn possess maximum health benefits.

scholarly journals From Physics Model to Results: An Optimizing Framework for Cross-Architecture Code Generation

2013 ◽  
Vol 21 (1-2) ◽  
pp. 1-16 ◽  
Author(s):  
Marek Blazewicz ◽  
Ian Hinder ◽  
David M. Koppelman ◽  
Steven R. Brandt ◽  
Milosz Ciznicki ◽  
...  
Keyword(s):  
Code Generation ◽  
High Performance ◽  
Large Scale ◽  
Einstein Equations ◽  
Efficient Manner ◽  
Code Transformations ◽  
Wide Range ◽  
Problem Description ◽  
Physics Model ◽  
High Level

Starting from a high-level problem description in terms of partial differential equations using abstract tensor notation, theChemoraframework discretizes, optimizes, and generates complete high performance codes for a wide range of compute architectures. Chemora extends the capabilities of Cactus, facilitating the usage of large-scale CPU/GPU systems in an efficient manner for complex applications, without low-level code tuning. Chemora achieves parallelism through MPI and multi-threading, combining OpenMP and CUDA. Optimizations include high-level code transformations, efficient loop traversal strategies, dynamically selected data and instruction cache usage strategies, and JIT compilation of GPU code tailored to the problem characteristics. The discretization is based on higher-order finite differences on multi-block domains. Chemora's capabilities are demonstrated by simulations of black hole collisions. This problem provides an acid test of the framework, as the Einstein equations contain hundreds of variables and thousands of terms.

scholarly journals [ANT]: A Machine Learning Approach for Building Performance Simulation: Methods and Development

2019 ◽  
Vol 3 (1) ◽  
pp. 205
Author(s):  
Mahmoud M. Abdelrahman ◽  
Ahmed Mohamed Yousef Toutou
Keyword(s):  
Machine Learning ◽  
High Performance ◽  
General Purpose ◽  
Ease Of Use ◽  
Building Performance ◽  
Performance Simulation ◽  
Building Performance Simulation ◽  
Wide Range ◽  
Performance Development ◽  
High Level

In this paper, we represent an approach for combining machine learning (ML) techniques with building performance simulation by introducing four methods in which ML could be effectively involved in this field i.e. Classification, Regression, Clustering and Model selection . Rhino-3d-Grasshopper SDK was used to develop a new plugin for involving machine learning in design process using Python programming language and making use of scikit-learn module, that is, a python module which provides a general purpose high level language to nonspecialist user by integration of wide range supervised and unsupervised learning algorithms with high performance, ease of use and well documented features. ANT plugin provides a method to make use of these modules inside Rhino\Grasshopper to be handy to designers. This tool is open source and is released under BSD simplified license. This approach represents promising results regarding making use of data in automating building performance development and could be widely applied. Future studies include providing parallel computation facility using PyOpenCL module as well as computer vision integration using scikit-image.

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