A new solution to the coupled problems of aero-propulsion system deceleration under supersonic state

2021 ◽  
pp. 095440622110528
Author(s):  
Fengyong Sun ◽  
Chunsheng Ji ◽  
Tengfei Zhang
Keyword(s):  
Integrated Control ◽  
Control Variable ◽  
Propulsion System ◽  
Effective Control ◽  
Coupled Problems ◽  
Component Level ◽  
Turbofan Engine ◽  
Control Scheme ◽  
Level Model ◽  
Rapid Drop

Under supersonic state, the aero-propulsion system exhibits different coupled characters in deceleration from that in acceleration. However, the deceleration control has not been fully studied. In order to solve the coupled problems, an integrated component-level model including inlet and turbofan engine was established. Based on the integrated model, the particularity of inlet adjustment during deceleration was analyzed. And the analyzed results showed that the inlet regulation is not necessary to keep the inlet and engine working in well-matched at any time under supersonic state. Due to the coupled relationship between inlet and turbofan engine, a new optimal integrated control scheme is proposed in this paper. The inlet ramp angle is taken as an optimal control variable as the same as main fuel mass flow and nozzle throat area. The simulation results indicate that inlet ramp angle regulation showed a more effective control quality in the rapid drop of aero-propulsion–installed thrust. Furthermore, the deceleration could be completed in a shorter control time.

Study of Fuzzy Control for Turbofan Engine Based on Improved Genetic Algorithms Optimization

2011 ◽  
Vol 148-149 ◽  
pp. 1072-1076
Author(s):  
Yu Hu ◽  
Yue Cheng Yang ◽  
Shi Ying Zhang ◽  
Xi Xing Yu
Keyword(s):  
Fuzzy Control ◽  
Fuzzy Controller ◽  
Improved Genetic Algorithm ◽  
Control Effect ◽  
Component Level ◽  
Turbofan Engine ◽  
Control Precision ◽  
Level Model ◽  
Fuzzy Control Algorithm ◽  
Great Control

In the paper, the fuzzy control algorithm was studied in turbofan engine. The turbofan engine models of “little deflection” model and “large deflection” model were built based on component level model. Then, a fuzzy controller, including the fuzzy-integral mixed controller, smith forecast and compensation, was designed with the fuzzy rules were optimized by improved genetic algorithm. The simulation results show that the designed control system responds fast, has no overshoot or oscillation, and the control precision is high. The controller can effectively solve time delay influence with a great control effect for “little deflection” model and acceleration model.

Multi-Variable Control of an Integrated Propulsion and Airframe System

1995 ◽  
Vol 209 (3) ◽  
pp. 179-190
Author(s):  
R A Perez
Keyword(s):  
Dynamical System ◽  
Feedback Loop ◽  
Closed Loop ◽  
Integrated Control ◽  
Sufficient Conditions ◽  
Turbofan Engine ◽  
Variable Control ◽  
Control Scheme ◽  
Necessary And Sufficient ◽  
Control Methodology

The development of an integrated control scheme to enhance the performance of a generic interconnected multi-variable dynamical system, consisting of a turbofan engine and an airframe, in the presence of predominantly destructive dynamical interactions over the flight envelope is considered in this paper. The control scheme consists of two components: a simple static forward loop or feedback loop precompensator to improve the interactions followed by a forward or feedback loop controller to improve the performance. The system must be tolerant to soft and hard output sensor failures by means of analytic redundancy only. A control methodology to satisfy the above specifications is presented here. Necessary and sufficient conditions are presented in order to achieve a stable closed-loop performance of the overall system by tuning every loop separately, that is decentralized stability.

scholarly journals Control of Solvent-Based Post-Combustion Carbon Capture Process with Optimal Operation Conditions

Processes ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 366 ◽  
Author(s):  
Yih-Hang Chen ◽  
Ming-Tien Shen ◽  
Hsuan Chang ◽  
Chii-Dong Ho
Keyword(s):  
Carbon Capture ◽  
Control Variable ◽  
High Energy ◽  
Optimal Operation ◽  
Capture Efficiency ◽  
Effective Control ◽  
Capture Process ◽  
Set Point ◽  
Control Scheme ◽  
Control Schemes

Solvent-based post-combustion carbon capture (PCC) is a mature and essential technology to solve the global warming problem. The high energy consuming issue and the flexible operation required by the power plants inquire about the development of effective control systems for PCC plants. This study proposes the optimal-based control approach that utilizes optimal set-point values for the quality controllers. The five optimal-based control schemes studied all employed L/G (liquid to gas ratio in absorber) as one quality control variable. Performance comparisons with a typical conventional control scheme are conducted employing a rate-based dynamic model for the MEA (monoethanolamine) solvent PCC process developed on a commercial process simulator. Compared to the typical control scheme, the optimal-based control schemes provide faster responses to the disturbance changes from the flue gas conditions and the set-point change of the CO2 capture efficiency, as well as better results in terms of IAEs (integral of absolute errors) of capture efficiency and reboiler heat duty during the stabilization period. LG-Tstr and LG-Tabs-Cascade are the best schemes. In addition to L/G, these two schemes employ the control of Tstr (the temperature of a stage of stripper) and a cascade control of Tabs (the temperature of a stage of absorber) (outer loop) and Tstr (inner loop), respectively.

Study on integrated control for supersonic inlet and turbofan engine model

2020 ◽  
pp. 095441002094406
Author(s):  
Haoying Chen ◽  
Haibo Zhang ◽  
Yao Du ◽  
Qiangang Zheng
Keyword(s):  
Control Method ◽  
Integrated Control ◽  
Pressure Ratio ◽  
Normal Shock ◽  
Component Level ◽  
Recovery Coefficient ◽  
Turbofan Engine ◽  
Engine Model ◽  
Supersonic Inlet ◽  
Shock Position

Considering the supersonic inlet model with normal shock position feedback, the integrated control method of inlet and turbofan engine is studied. The integrated model includes the supersonic inlet model and the component level model of engine. Combining the relationship between the normal shock position and the total pressure recovery coefficient, the supersonic inlet and engine model is constructed. On the basis of this model, the normal shock position closed-loop control simulation is carried out, which shows that the normal shock position matching point could be stabilized near the optimal value while restraining the inlet stream disturbance. Furthermore, based on the H∞ control algorithm, an inlet and engine integrated control is designed to control the installation thrust and turbine pressure ratio with fuel, nozzle throat area, and normal shock position as control variables. The simulation results show that the response time of the integrated control is faster than the independent control. The integrated control has stronger ability to restrain the atmospheric disturbance, which could ensure the stable and reliable operation of the propulsion system.

scholarly journals Review of Intelligent Control Systems for Natural Ventilation as Passive Cooling Strategy for UK Buildings and Similar Climatic Conditions

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4388
Author(s):  
Esmail Mahmoudi Saber ◽  
Issa Chaer ◽  
Aaron Gillich ◽  
Bukola Grace Ekpeti
Keyword(s):  
Control Systems ◽  
Natural Ventilation ◽  
Energy Use ◽  
Integrated Control ◽  
Climatic Conditions ◽  
Effective Control ◽  
Practical Implementation ◽  
Optimal Output ◽  
Heating And Cooling ◽  
Building Cooling

Natural ventilation is gaining more attention from architects and engineers as an alternative way of cooling and ventilating indoor spaces. Based on building types, it could save between 13 and 40% of the building cooling energy use. However, this needs to be implemented and operated with a well-designed and integrated control system to avoid triggering discomfort for occupants. This paper seeks to review, discuss, and contribute to existing knowledge on the application of control systems and optimisation theories of naturally ventilated buildings to produce the best performance. The study finally presents an outstanding theoretical context and practical implementation for researchers seeking to explore the use of intelligent controls for optimal output in the pursuit to help solve intricate control problems in the building industry and suggests advanced control systems such as fuzzy logic control as an effective control strategy for an integrated control of ventilation, heating and cooling systems.

Aero-engine dynamic model based on an improved compact propulsion system dynamic model

2021 ◽  
pp. 095965182098408
Author(s):  
Qiangang Zheng ◽  
Yong Wang ◽  
Chongwen Jin ◽  
Haibo Zhang
Keyword(s):  
Dynamic Model ◽  
Propulsion System ◽  
System Dynamic ◽  
Inlet Temperature ◽  
System Dynamic Model ◽  
Component Level ◽  
Engine Model ◽  
Surge Margin ◽  
Aero Engine ◽  
Engine Dynamic

The modern advanced aero-engine control methods are onboard dynamic model–based algorithms. In this article, a novel aero-engine dynamic modeling method based on improved compact propulsion system dynamic model is proposed. The aero-engine model is divided into inlet, core engine, surge margin and nozzle models for establishing sub-model in the compact propulsion system dynamic model. The model of core engine is state variable model. The models of inlet, surge margin and nozzle are nonlinear models which are similar to the component level model. A new scheduling scheme for basepoint control vector, basepoint state vector and basepoint output vector which considers the change of engine total inlet temperature is proposed to improve engine model accuracy especially the steady. The online feedback correction of measurable parameters is adopted to improve the steady and dynamic accuracy of model. The modeling errors of improved compact propulsion system dynamic model remain unchanged when engine total inlet temperature of different conditions are the same or changes small. The model accuracy of compact propulsion system dynamic model, especially the measurable parameters, is improved by online feedback correction. Moreover, the real-time performance of compact propulsion system dynamic model and improved compact propulsion system dynamic model are much better than component level model.

A suspension system with quasi-zero stiffness characteristics and inerter nonlinear energy sink

2020 ◽  
pp. 107754632097290
Author(s):  
You-cheng Zeng ◽  
Hu Ding ◽  
Rong-Hua Du ◽  
Li-Qun Chen
Keyword(s):  
Integrated Control ◽  
Harmonic Approximation ◽  
Nonlinear Energy Sink ◽  
Suspension System ◽  
Degree Of Freedom ◽  
System Parameters ◽  
Suspension Systems ◽  
Control Scheme ◽  
Energy Sink ◽  
Nonlinear Energy

In this article, a novel vibration control scheme of suspension systems is proposed. It combines the advantages of quasi-zero stiffness isolator, nonlinear energy sink absorber, and inerter. This proposed scheme can achieve low transmissibility, low amplitude, and low additional weight and resolve the conflict between riding comfort and handling stability. Strong nonlinear vibration equations of a quarter-vehicle suspension system are established. It also presents the detailed process of high-order harmonic approximation to obtain steady-state responses. Moreover, approximate solutions are validated by a numerical method. Furthermore, based on riding comfort and handling stability, the following four suspension systems are evaluated and compared, namely, 2-degree-of-freedom quarter-vehicle model, 2-degree-of-freedom quarter-vehicle with quasi-zero stiffness isolator, 2-degree-of-freedom quarter-vehicle with inerter-nonlinear energy sink absorber, and 2-degree-of-freedom quarter-vehicle integrated control scheme with quasi-zero stiffness and inerter-nonlinear energy sink. It is found that the integrated control scheme with quasi-zero stiffness and inerter-nonlinear energy sink can significantly improve the riding comfort and handling stability at the same time. In addition, the effects of system parameters are studied carefully. The results show that based on the reasonable design of the control system parameters, better riding comfort and handling stability can be obtained. In short, this article provides a theoretical basis for integrating quasi-zero stiffness isolators and inerter-nonlinear energy sink absorbers to improve the riding comfort and handling stability.

Research on Integrated Control System of the Gas Pressure in Coke Oven

2013 ◽  
Vol 397-400 ◽  
pp. 1214-1219
Author(s):  
Xia Bai ◽  
Da Lu Guan ◽  
Chen Rui
Keyword(s):  
Control System ◽  
Control Strategies ◽  
Integrated Control ◽  
Control Object ◽  
Coke Oven ◽  
Pressure Control ◽  
Expert Control ◽  
Control Scheme ◽  
Hardware Reliability ◽  
Pressure Control System

This paper combines hardware reliability and software mobility with modern intelligent control through the analysis of the control object using intelligent decoupling control scheme to control the pressure control system of the large gas collector in coke oven. By using expert control strategies based on the DCS, the paper develops the system design which is versatile and effective.

A Component-Centric Approach to Structural Analysis of Mechanisms

2014 ◽  
Author(s):  
Christopher Stack ◽  
Subha Kumpaty ◽  
Mohammad Mahinfalah
Keyword(s):  
Structural Analysis ◽  
Coordinate System ◽  
The Other ◽  
Component Level ◽  
Unique Problem ◽  
Separate Model ◽  
Loading Effects ◽  
Level Model ◽  
Good Trade ◽  
The Individual

Structural analyses of mechanisms with components that move relative to each other provide a unique problem to the analyst building and running structural models. In these situations, the analyst usually has to either simplify the problem to a point where the results are unusable or maintain multiple models, which will take more effort to maintain and more resources to run the models. If a mechanism is simplified down to just analyzing one component at a time without regard for the other components in the system, the results will not be accurate because the loading effects of the other components will not be accounted for. In cases where all the components are included in the model the loading effects from the other components will be accounted for, however, a separate model will be required for each position. This paper presents a method of breaking down the complex mechanism into a component level model for each part of the assembly, while still accounting for all loading effects of the other components; in the Pivot Method the component under analysis stays stationary and the loading moves around the component to represent the different positions that it can take. In order to accomplish this task, a simplified model is used to generate loads at each of the joints. Once the pivot loads are known, a spreadsheet can be used to transform the loads to a coordinate system in which the individual component is being modeled. With the pivot loads known and all the loads transformed into the proper coordinate system the structural analysis of the component under investigation can continue. The intention of this paper is to introduce the Pivot Method and to demonstrate that it provides a good trade off between both the complexity of methods that model the assembly as a system, and those that focus on the component under question alone. To accomplish this, the analysis results of the Pivot Method models will be compared to results obtained from other methods, with the intention of showing that the Pivot Method will provide the same results while requiring less effort to model and less resources to run.

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