Dynamic modeling of a cabin pressure control system

2019 ◽  
Vol 234 (2) ◽  
pp. 401-415
Author(s):  
Kanhaiya Lal Chaurasiya ◽  
Bishakh Bhattacharya ◽  
AK Varma ◽  
Sarthak Rastogi
Keyword(s):  
Control System ◽  
Mathematical Models ◽  
Air Flow ◽  
Control Valve ◽  
Pressure Control ◽  
Absolute Pressure ◽  
Control Chamber ◽  
Matlab Program ◽  
Pressure Control System ◽  
Pressure Control Valve

Cabin pressure control system of an aircraft maintains cabin pressure in all flight modes as per the aircraft cabin pressurization characteristics by controlling the air flow from the cabin through the outflow valve of the cabin pressure control valve. The movement of outflow valve in turn depends on the air flow from the control chamber of cabin pressure control valve, which is controlled by the clapper and the poppet valves. These valves are actuated by absolute pressure and the differential pressure capsules, respectively depending upon the operating flight conditions. Mathematical models have been developed to simulate the air outflow rates from the cabin and the control chamber of cabin pressure control valve during steady-state and transient flight conditions. These mathematical models have then been translated into a MATLAB program to obtain plots of cabin pressures as a function of aircraft altitudes. The mathematical models are validated for standard cabin pressurization characteristics of a multirole light fighter/trainer aircraft. The model developed, thus can be used to produce a number of variants of cabin pressure control valve to suit different cabin pressurization characteristics.

Modeling and Stability of a Hydraulic Load-Sensing Pump With Investigation of a Hard Nonlinearity in the Pump Displacement Control System

2014 ◽  
Author(s):  
Zachary D. Wagner ◽  
Roger Fales
Keyword(s):  
Control System ◽  
Stability Analysis ◽  
Flow Control ◽  
Control Valve ◽  
Pressure Control ◽  
Flow Control Valve ◽  
Pump System ◽  
Load Sensing ◽  
Pressure Control System ◽  
The Stability

Certain types of Load-sensing (LS) pumps utilize a hydro-mechanical control system designed to regulate the pressure difference, or margin pressure, between the inlet and outlet of a flow control valve. With a constant margin pressure, predictable flow control can be achieved by controlling the orifice area of the flow control valve. In this work, the stability of the pressure control system will be investigated. A combination of linear analysis and nonlinear analysis is employed to assess the stability of a particular LS pump system. Among many nonlinearities present in the hydro-mechanical system, of particular interest is the saturation inherent in the actuator that is used to displace the pump swash plate and the saturation within the 3-way spool valve that permits flow to reach the actuator. This saturation nonlinearity has been isolated from the rest of the system to enable stability analysis. Analysis of model characteristics is used to make conclusions about the stability of the system consisting of interconnected linear and nonlinear portions. The stability analysis is compared to results obtained through a simulation study using a nonlinear model based on first principles.

Performance Improvement of Gas Liquid Cylindrical Cyclone Separators Using Integrated Level and Pressure Control Systems

2000 ◽  
Vol 122 (4) ◽  
pp. 185-192 ◽  
Author(s):  
Shoubo Wang ◽  
Ram S. Mohan ◽  
Ovadia Shoham ◽  
Jack D. Marrelli ◽  
Gene E. Kouba
Keyword(s):  
Control System ◽  
Integrated Control ◽  
Control Valve ◽  
Pressure Control ◽  
Rate Region ◽  
Cylindrical Cyclone ◽  
Pressure Control System ◽  
Carry Over ◽  
Operational Envelope ◽  
Integrated Control System

The performance of gas-liquid cylindrical cyclone (GLCC©) separators for two-phase flow metering loop can be improved by eliminating liquid overflow into the gas leg or gas blow-out through the liquid leg, utilizing suitable integrated control systems. In this study, a new integrated control system has been developed for the GLCC, in which the control is achieved by a liquid control valve in the liquid discharge line and a gas control valve in the gas discharge line. Simulation studies demonstrate that the integrated level and pressure control system is highly desirable for slugging conditions. This strategy will enable the GLCC to operate at constant pressure so as not to restrict well flow and simultaneously prevent liquid carry-over and gas carry-under. Detailed experimental studies have been conducted to evaluate the improvement in the GLCC operational envelope for liquid carry-over with the integrated level and pressure control system. The results demonstrate that the GLCC equipped with integrated control system is capable of controlling the liquid level and GLCC pressure for a wide range of flow conditions. The experimental results also show that the operational envelope for liquid carry-over is improved twofold at higher liquid flow rate region and higher gas flow rate region. GLCC performance is also evaluated by measuring the operational envelope for onset of gas carry-under. [S0195-0738(00)00804-9]

PRESSURE CONTROL SYSTEM AT CEMENTATION OF WELLS

2017 ◽  
pp. 62-67
Author(s):  
V. G. Kuznetsov ◽  
O. A. Makarov
Keyword(s):  
Control System ◽  
Oil And Gas ◽  
Pressure Control ◽  
Poor Quality ◽  
Technical Solution ◽  
Cement Slurry ◽  
Automated Control ◽  
Injection Speed ◽  
Pressure Control System ◽  
Effective Life

At cementing of casing of oil and gas wells during the process of injecting of cement slurry in the casing column the slurry can move with a higher speed than it’s linear injection speed. A break of continuity of fluid flow occurs, what can lead to poor quality isolation of producing formations and shorten the effective life of the well. We need to find some technical solution to stabilize the linear velocity of the cement slurry in the column. This task can be resolved with an automated control system.

Development of a Pressure Control System for Brace Treatment of Scoliosis

2012 ◽  
Vol 20 (4) ◽  
pp. 557-563 ◽  
Author(s):  
Eric Chalmers ◽  
Edmond Lou ◽  
Doug Hill ◽  
Vicky H. Zhao ◽  
Man-Sang Wong
Keyword(s):  
Control System ◽  
Pressure Control ◽  
Brace Treatment ◽  
Pressure Control System

Real-Time Micro-Fluidic Chip Pressure Control System Base on the Optical Interference

2014 ◽  
Vol 494-495 ◽  
pp. 1274-1277
Author(s):  
Kan Liu ◽  
Hao You
Keyword(s):  
Control System ◽  
Real Time ◽  
Measurement System ◽  
Interference Fringe ◽  
Pressure Control ◽  
Measured Data ◽  
Optical Interference ◽  
Interference Fringes ◽  
Pressure Control System

This article introduces a measurement system based on LabVIEW used for optical interference fringe on micro-fluidic chips. This system mainly uses cameras to capture real-time images of wedge interference fringe on micro-fluidic chips, then the collected images will be binarized by LabVIEW. The processed images will be divided by zone , determine the flatness and gap thickness of the micro-fluidic chips by interference fringes with different directions of deflection and numbers. Finally, feedback from measured data will be used to adjust the flatness and gap thickness of micro-fluidic chips in order to meet the requirement of tests.

Fuzzy Control-Based Air-Compressor Constant Pressure Gas Intelligent Control

2011 ◽  
Vol 230-232 ◽  
pp. 187-191
Author(s):  
Gong Fa Li ◽  
Si Qiang Xu ◽  
Jin Hui Wang ◽  
Jin Tang Yang ◽  
Jian Yi Kong ◽  
...  
Keyword(s):  
Control System ◽  
Fuzzy Control ◽  
Constant Pressure ◽  
Pressure Control ◽  
Air Compressor ◽  
Time Varying Delay ◽  
Important Sense ◽  
Pressure Control System ◽  
Working Characteristic ◽  
Varying Delay

The air compressor system is a time-varying, delay and nonlinear complex system, it has a very important sense to ensure that the supply pressure is stable in the compressor control system. According to the working characteristic of air compressor system, the fuzzy control theory, as one of the modern control theories, was applied into the constant pressure control system to design a fuzzy pressure controller. The simulation results show that the controller was more convenient and effective; it has certain directive significance and reference for the other parameter’s control of air compressor system.

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