Control of Piston Position in Inviscid Gas by Bilateral Boundary Actuation

2018 ◽  
Author(s):  
Mona Buisson-Fenet ◽  
Shumon Koga ◽  
Miroslav Krstic
Keyword(s):  
Inviscid Gas ◽  
Piston Position

The potential subcritical flow of an inviscid gas past multiparametric profiles

1969 ◽  
Vol 5 (12) ◽  
pp. 1330-1335
Author(s):  
V. I. Putyata ◽  
G. I. Musienko
Keyword(s):  
Subcritical Flow ◽  
Inviscid Gas

Average Modeling and Nonlinear Observer Design For Pneumatic Actuators With On/Off Solenoid Valves

2021 ◽  
Author(s):  
Khaled Laib ◽  
Minh Tu Pham ◽  
Xuefang LIN-SHI ◽  
Redha Meghnous
Keyword(s):  
Closed Loop ◽  
Sliding Mode ◽  
High Gain ◽  
Observer Design ◽  
Nonlinear Observer ◽  
State Model ◽  
Pressure Measurements ◽  
Pneumatic Actuators ◽  
Nonlinear Observers ◽  
Piston Position

Abstract This paper presents an averaged state model and the design of nonlinear observers for an on/off pneumatic actuator. The actuator is composed of two chambers and four on/off solenoid valves. The elaborated averaged state model has the advantage of using only one continuous input instead of four binary inputs. Based on this new model, a high gain observer and a sliding mode observer are designed using the piston position and the pressure measurements in one of the chambers. Finally, their closed-loop performances are verified and compared on an experimental benchmark.

Modeling and Pressure-Based Force Control of a Hydraulic Actuator

1997 ◽  
Author(s):  
Scott M. Lyon ◽  
Mark S. Evans
Keyword(s):  
Dynamic Model ◽  
Force Control ◽  
Feedback Linearization ◽  
External Surface ◽  
Bond Graph ◽  
Hydraulic Pressure ◽  
Velocity Control ◽  
Hydraulic Actuator ◽  
Spool Valve ◽  
Piston Position

Abstract A dynamic model of a hydraulic actuator/spool valve combination is developed using the bond graph method. Feedback linearization is used to develop a force controller for the system using hydraulic pressure in each chamber of the actuator along with piston position and velocity as feedback. The use of a feedforward term to compensate for the seal friction within the actuator provides for a stable and accurate controller. Velocity control is achieved through calculation of the reference force required to overcome the seal friction and produce the acceleration required to reach the desired velocity. It is shown that the use of such a force controller allows for an acceptable transition from velocity to force control when the piston comes in contact with an external surface.

Computational Study of Fuel Injection in a Large-Bore Gas Engine

2003 ◽  
Author(s):  
Snehaunshu Chowdhury ◽  
Razi Nalim ◽  
Thomas M. Sine
Keyword(s):  
High Pressure ◽  
Fuel Injection ◽  
Computational Study ◽  
Turbulence Models ◽  
Fuel Flow ◽  
Air Mixing ◽  
Instantaneous Pressure ◽  
Combustion Processes ◽  
High Pressure Injection ◽  
Piston Position

Emission controls in stationary gas engines have required significant modifications to the fuel injection and combustion processes. One approach has been the use of high-pressure fuel injection to improve fuel-air mixing. The objective of this study is to simulate numerically the injection of gaseous fuel at high pressure in a large-bore two-stroke engine. Existing combustion chamber geometry is modeled together with proposed valve geometry. The StarCD® fluid dynamics code is used for the simulations, using appropriate turbulence models. High-pressure injection of up to 500 psig methane into cylinder air initially at 25 psig is simulated with the valve opened instantaneously and piston position frozen at the 60 degrees ABDC position. Fuel flow rate across the valve throat varies with the instantaneous pressure but attains a steady state in approximately 22 ms. As expected with the throat shape and pressures, the flow becomes supersonic past the choked valve gap, but returns to a subsonic state upon deflection by a shroud that successfully directs the flow more centrally. This indicates the need for careful shroud design to direct the flow without significant deceleration. Pressures below 300 psig were not effective with the proposed valve geometry. A persistent re-circulation zone is observed immediately below the valve, where it does not help promote mixing.

Sign in / Sign up

Export Citation Format

Share Document