Modeling and Dynamic Evaluation of a Two-Stage Two-Spool Servovalve Used for Pressure Control

1991 ◽  
Vol 113 (4) ◽  
pp. 709-713 ◽  
Author(s):  
S. T. Tsai ◽  
A. Akers ◽  
S. J. Lin
Keyword(s):  
Mathematical Model ◽  
Control Valve ◽  
Pressure Control ◽  
Experimental Results ◽  
Two Stage ◽  
Dynamic Evaluation ◽  
Second Stage ◽  
Experimental Values ◽  
Pressure Control Valve ◽  
Good Agreement

Experimental results for a unique design of a two-spool pressure control valve were reported by Anderson (1984). The first stage is a dynamically stable flapper-nozzle valve for which a mathematical model is already available (Lin and Akers, 1989a). For the second stage, however, which consists of two parallel spools in a common body, no such model existed. The purpose of this paper was therefore to construct such a model and to compare results calculated from it to experimental values. Moderately good agreement with experimental values was obtained.

scholarly journals The Miller tracheal cuff pressure control valve.

Anaesthesia ◽  
1993 ◽  
Vol 48 (4) ◽  
pp. 324-327 ◽  
Author(s):  
K. A. PAYNE ◽  
D. M. MILLER
Keyword(s):  
Cuff Pressure ◽  
Control Valve ◽  
Pressure Control ◽  
Pressure Control Valve ◽  
Tracheal Cuff

Suction Pressure Control Valve for Microneurosurgery

2020 ◽  
Vol 68 (3) ◽  
pp. 652
Author(s):  
DeepakK Jha ◽  
AbhijeetS Barath ◽  
OmP Thakur ◽  
Mayank Garg ◽  
Suryanarayanan Bhaskar
Keyword(s):  
Control Valve ◽  
Pressure Control ◽  
Suction Pressure ◽  
Pressure Control Valve

Modelling and Reducing Fuel Flow Pulsation of a Fuel-Metering System by Improving Response of the Pressure Control Valve During Pump Mode Switching in a Turbofan Engine

2019 ◽  
Author(s):  
Seiei Masuda ◽  
Fumio Shimizu ◽  
Masaki Fuchiwaki ◽  
Kazuhiro Tanaka
Keyword(s):  
Control Valve ◽  
Flow Region ◽  
Pressure Control ◽  
Low Flow ◽  
Mode Switching ◽  
Pump Mode ◽  
Turbofan Engine ◽  
Fuel Pump ◽  
Fuel Flow ◽  
Pressure Control Valve

Abstract In an aircraft turbofan engine, a fuel metering unit meters and supplies the required fuel to the engine according to the flight situation. When a centrifugal fuel pump (CFP) is used as the fuel pump, the ratio of hydraulic power per weight can be increased by raising the rated rotational speed, so the weight of the fuel pump can be decreased compared to when using a gear pump (GFP). There is an advantage that it can be reduced significantly. However, since the operating range of the fuel pump is wide, it is not effective to use CFP in an extremely low flow rate region because the fuel temperature rises due to its PQ characteristics and a large loss. Therefore, it is considered effective to combine CFP and GFP as pressure sources, and to use GFP in the low flow region and CFP in the high flow region. For that purpose, it is necessary to have a pump mode switching mechanism. The disadvantage in this case is that changing the pump mode causes a large pressure change of the fuel pressure source, which in turn causes fuel flow pulsations. There are three possible ways to solve this problem. The first method is to keep the differential pressure control valve (DPCV) unit response constant, which keeps the metering valve differential pressure constant in FMS. A second method is to remove high frequency components that the DPCV cannot follow pressure changes in the fuel control system. A third method is to keep the pressure difference between the two fuel sources small and to reduce the amplitude of the applied disturbance. In this paper, the first method, which makes DPCV response high response, is verified by modeling and simulation, and its effectiveness is confirmed.

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