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Research on Verification and Validation of Turbofan Engine performance model

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Research on Verification and Validation of Turbofan Engine P...

performance Analytical model of IEEE 802.11 Distributed Coordination Function

第40届中国控制会议

作者： Kui Liu Pan Wang Qing Li Department of Automation Tsinghua University Aero-Engine Academy of China

Turbofan engine performance model plays an important role on engine R＆D（Research ＆ Development） and *** precision engine model can obtain full accurate test parameters. It can be exposed the problem as soon as possible and shorten the development cycle. Based on the methodology of verification and validation, the paper evaluates the accuracy and uncertainty of turbofan engine model qualitatively and quantitatively from the perspective of modeling and simulation. Taking the design point calculation of twin-spool turbofan engine as an example, it studies the verification and validation process based on self-developed software. The verification contains code verification and calculation verification. The verification demonstrates the accuracy based on numerical solution algorithm. The validation is compared with real test data and demonstrates the accuracy in particular applications. The final accuracy and uncertainty of performance model are given by verification and validation. It can assist to establish the verification and validation system extending the method to non-design points and transition states. It is of great significance to the engineering application of simulation model.

关键词： Turbofan Engine performance model Verification Validation

来源： cnki会议评论

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Journal of Donghua University(English Edition) 2006年第1期23卷 21-26页

作者：朱容波杨宇航 Department of Electronic Engineering Shanghai Jiaotong UniversityShanghai 200030

IEEE 802.11 distributed coordination function （DCF） is a distributed medium access scheme based on carrier sense multiple access with collision avoidance （CSMA/CA） protocol. Many literatures have analyzed the performance of IEEE802.11 DCF. However, such literatures either used simulation methods or built the analytical models under the assumption that the saturation condition was satisfied. To overcome such a problem, in this paper, a hi-dimensional Markovian model has been introduced to depict the DCF mechanism. The proposed model introduced an idle stage and a discrete time M/G/1 queue to deduce the channel throughput under finite load traffic. Simulation results proved the accuracy of the proposed model.

关键词： IEEE 802.11 DCF performance model

performance modeling of positive degraded task-pair with helper-thread in CMP

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High Technology Letters 2010年第3期16卷 221-226页

作者： Gu Zhimin Zheng Ninghan Zhang Yi Liu Changding Tang Jie Huang Yan School of Computer Science and Technology Beijing Institute of Technology Beijing 100081 P.R. China School of Computer Science and Technology Tsinghua University Beijing 100081 P.R. China

Helper-thread of a task can hide the memory access time of irregular data on the chip muhi-core processor （CMP）. For constructing a compiler that effectively supports the helper-thread of a task in the multi-core scenario based on the last level shared cache, this paper studies its performance stable condi- tions. Unfortunately, there is no existing model that allows extensive investigation of the impact of stable conditions, we present the base of pre-computation that is formalized by our degraded task-pair 〈 T, T＇〉 with the helper-thread, and its stable conditions are analyzed. Finally, a novel performance model and a constructing method of pre-computation based on our positive degraded task-pair are proposed. The efficient results are shown by our experiments. If we further exploit memory level parallelism （MLP） for our task-pair, the task-pair 〈 T, T＇〉 can reach better performance.

关键词： chip multi-core processor (CMP) helper-thread pre-computation performance model

The Big Chip:Challenge,model and architecture

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Fundamental Research 2024年第6期4卷 1431-1441页

作者： Yinhe Han Haobo Xu Meixuan Lu Haoran Wang Junpei Huang Ying Wang Yujie Wang Feng Min Qi Liu Ming Liu Ninghui Sun Institute of Computing Technology Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100190China University of Science and Technology of China Hefei 230026China Zhejiang Lab Hangzhou 311100China Fudan University Shanghai 200433China

As Moore’s Law comes to an end,the implementation of high-performance chips through transistor scaling has become increasingly *** improve performance,increasing the chip area to integrate more transistors has become an essential ***,due to restrictions such as the maximum reticle area,cost,and manufacturing yield,the chip’s area cannot be continuously increased,and it encounters what is known as the“area-wall”.In this paper,we provide a detailed analysis of the area-wall and propose a practical solution,the Big Chip,as a novel chip form to continuously improve *** introduce a performance model for evaluating Big Chip and discuss its ***,we derive the future development trends of the Big Chip.

关键词： Big Chip Integrated chips Area-wall Chiplet performance model

A new component maps correction method using variable geometric parameters

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Chinese Journal of Aeronautics 2021年第4期34卷 360-374页

作者： Shaochen LI Hailong TANG Min CHEN School of Energy and Power Engineering Beihang UniversityBeijing 100083China Aircraft Engine Integrated System Safety Beijing Key Laboratory Beijing 100083China

Accurate engine performance models are important for model-based performance evaluation of aero *** accuracy of the model often depends on engine component maps,so there is a need for a method that can accurately correct the component maps of the model over a wide *** this paper,a new method for modifying component maps is proposed,this method combines the correction of the scaling factors with the solution process of the off-design working point,and uses the adjustment of the variable geometric parameters of the engine to change the position of the working line,in order to obtain more correction results and guarantee high accuracy in a wider *** method is validated by taking the main fan of the Adaptive Cycle Engine(ACE),an ideal power unit for a new generation of multi-purpose and ultra-wide working range aircraft,as an *** results show that the maximum error between the corrected component maps and the target maps is less than 1%.New possibility for more precise component maps can be realized in this paper.

关键词： Adaptive cycle engine Component map correction performance model Scaling factor Variable geometric parameter

QAAS:quick accurate auto-scaling for streaming processing

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Frontiers of Computer Science 2024年第1期18卷 5-15页

作者： Shiyuan LIU Yunchun LI Hailong YANG Ming DUN Chen CHEN Huaitao ZHANG Wei LI State Key Laboratory of Software Development Environment Beijing 100191China School of Computer Science and Engineering Beihang UniversityBeijing 100191China School of Cyber Science and Technology Beihang UniversityBeijing 100191China School of Computer Science and Technology Xi’an Jiaotong UniversityXi’an 710049China

In recent years,the demand for real-time data processing has been increasing,and various stream processing systems have *** the amount of data input to the stream processing system fluctuates,the computing resources required by the stream processing job will also *** resources used by stream processing jobs need to be adjusted according to load changes,avoiding the waste of computing *** present,existing works adjust stream processing jobs based on the assumption that there is a linear relationship between the operator parallelism and operator resource consumption(e.g.,throughput),which makes a significant deviation when the operator parallelism *** paper proposes a nonlinear model to represent operator *** divide the operator performance into three stages,the Non-competition stage,the Non-full competition stage,and the Full competition *** our proposed performance model,given the parallelism of the operator,we can accurately predict the CPU utilization and operator *** with actual experiments,the prediction error of our model is below 5%.We also propose a quick accurate auto-scaling(QAAS)method that uses the operator performance model to implement the auto-scaling of the operator parallelism of the Flink *** to previous work,QAAS is able to maintain stable job performance under load changes,minimizing the number of job adjustments and reducing data backlogs by 50%.

关键词： stream processing performance model auto-scaling

From laboratory to on-site operation:Reevaluation of empirically based electric water chiller models

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Building Simulation 2022年第2期15卷 213-232页

作者： Bin Zhang Shijun You Sheng Wang Xiaoxiao Ding Chuang Wang Yan Gao School of Environmental Science and Engineering Tianjin UniversityTianjin 300072China State Key Laboratory of Air-Conditioning Equipment and System Energy Conservation Zhuhai 519070China Guangdong Key Laboratory of Refrigeration Equipment and Energy Conservation Technology Zhuhai 519070China Beijing Key Laboratory of Heating Gas SupplyVentilating and Air Conditioning EngineeringBeijing University of Civil Engineering and ArchitectureBeijing 100044China Beijing Advanced Innovation Center for Future Urban Design Beijing University of Civil Engineering and ArchitectureBeijing 100044China

Chiller model is a key factor to building energy simulation and chiller performance *** spread of new types of electric water chillers that have higher performance and wider operating range,new challenges have been faced by building energy simulation tools and their chiller *** work takes a new type of electric water chiller as a case study and reevaluates eight typical empirically based models for predicting the energy performance of electric water chiller to verify whether they are suitable for the new type of chiller,using both laboratory test data from chiller manufacturer and online monitoring data from on-site operation of a central cooling plant with chillers of the same *** prediction ability of the chiller models(including model prediction accuracy and generation ability)in laboratory test and on-site operation situations are *** results show that the existing models can well describe the chiller performance in the laboratory test situation but perform poorly in the on-site operation *** the best two models in the laboratory dataset,the overall prediction errors of DOE-2 and GN model increase more than 250%and 75%respectively in the field *** big discrepancy of model prediction accuracy in the two situations is mainly due to the differences of evaporator and condenser water flow rates between the laboratory and on-site operation datasets,which indicates the limitations of the empirical chiller models and implies further research in future in order to improve the suitability and reliability of chiller model.

关键词： electric water chiller performance model model validation model prediction ability variable water flow rates

A multi-fidelity simulation method research on front variable area bypass injector of an adaptive cycle engine

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Chinese Journal of Aeronautics 2022年第4期35卷 202-219页

作者： Zhewen XU Ming LI Hailong TANG Min CHEN School of Energy and Power Engineering Beihang UniversityBeijing 100083China Aero Engine Academy of China Beijing 101300China Research Institute of Aero-Engine Beihang UniversityBeijing 102206China

Front Variable Area Bypass Injector(Front-VABI) is a component of the Adaptive Cycle Engine(ACE) with important variable-cycle features. The performance of Front-VABI has a direct impact on the performance and stability of ACE, but the current ACE performance model uses approximate models for Front-VABI performance calculation. In this work, a multi-fidelity simulation based on a de-coupled method is developed which delivers a more accurate calculation of the Front-VABI performance based on Computational Fluid Dynamics(CFD) simulation. This simulation method proposes a form of Front-VABI characteristic and its matching calculation method between it and the ACE performance model, constructs a coupling method between the(2-D) Front-VABI model and the(0-D) ACE performance model. The result shows, when ACE works in triple bypass mode, the approximate model cannot account for the effect of FrontVABI pressure loss on Core Driven Fan Stage(CDFS) design pressure ratio, and the calculated error of high-pressure turbine inlet total temperature is more than 40 K in mode transition condition(the transition operating condition between triple bypass mode and double bypass mode). In double bypass mode, the approximate model can better simulate the performance of FrontVABI by considering the local loss of area expansion. This method can be applied to the performance-optimized design of Front-VABI and the ACE control law design during mode transition.

关键词： Adaptive cycle engine Computational fluid dynamics Front variable area bypass injector Multi-fidelity simulation performance model

Reliable Estimation of Execution Time of MapReduce Program

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China Communications 2011年第6期8卷 11-18页

作者：杨肖孙建伶 Department of Computer Science and Technology Zhejiang University

As data volume grows, many enterprises are considering using MapReduce for its simplicity. However, how to evaluate the performance improvement before deployment is still an issue. Current researches of MapReduce performance are mainly based on monitoring and simulation, and lack mathematical models. In this paper, we present a simple but powerful performance model for the prediction of the execution time of a MapReduce program with limited resources. We study each component of MapReduce framework, and analyze the relation between the overall performance and the number of mappers and reducers based on our model. Two typical MapReduce programs are evaluated in a small cluster with 13 nodes. Experimental results show that the mathematical performance model can estimate the execution time of MapReduce programs reliably. According to our model, number of mappers and reducers can be tuned to form a better execution pipeline and lead to better performance. The model also points out potential bottlenecks of the framework and future improvement.

关键词： performance model MapReduce execution time