Real-time prevention of spots on thermionic cathodes in high-pressure ARC discharges

2012 ◽  
Author(s):  
P. G. C. Almeida ◽  
M. S. Benilov ◽  
M. D. Cunha ◽  
J. G. L. Gomes
Keyword(s):  
High Pressure ◽  
Real Time ◽  
Thermionic Cathodes ◽  
Arc Discharges

Simulating changes in shape of thermionic cathodes during operation of high-pressure arc discharges

2019 ◽  
Vol 52 (50) ◽  
pp. 504004 ◽  
Author(s):  
M D Cunha ◽  
H T C Kaufmann ◽  
D F N Santos ◽  
M S Benilov
Keyword(s):  
High Pressure ◽  
Thermionic Cathodes ◽  
Arc Discharges

Real-time Downhole Monitoring and Logging Reduced Mud Loss Drastically for High-Pressure Gas Wells in Tarim Basin, China

2008 ◽  
Author(s):  
ShunChang Wang ◽  
Xinquan Zheng ◽  
Chun Jiang Zheng ◽  
Bailin Wu ◽  
YiMing Jiang ◽  
...  
Keyword(s):  
High Pressure ◽  
Real Time ◽  
Tarim Basin ◽  
Gas Wells ◽  
Mud Loss ◽  
Downhole Monitoring

scholarly journals Data-driven Adaptive Thresholding Model for Real-time Valve Delay Estimation in Digital Pump/Motors

2020 ◽  
Author(s):  
Abdallah Chehade ◽  
Farid Breidi ◽  
Keith Scott Pate ◽  
John Lumkes
Keyword(s):  
High Pressure ◽  
Real Time ◽  
Domain Knowledge ◽  
Operating Conditions ◽  
Delay Model ◽  
Hydraulic Systems ◽  
Pressure Transducers ◽  
Statistical Behavior ◽  
Shift Detection ◽  
And Performance

Valve characteristics are an essential part of digital hydraulics. The on/off solenoid valves utilized on many of these systems can significantly affect the performance. Various factors can affect the speed of the valves causing them to experience various delays, which impact the overall performance of hydraulic systems. This work presents the development of an adaptive statistical based thresholding real-time valve delay model for digital Pump/Motors. The proposed method actively measures the valve delays in real-time and adapts the threshold of the system with the goal of improving the overall efficiency and performance of the system. This work builds on previous work by evaluating an alternative method used to detect valve delays in real-time. The method used here is a shift detection method for the pressure signals that utilizes domain knowledge and the system’s historical statistical behavior. This allows the model to be used over a large range of operating conditions, since the model can learn patterns and adapt to various operating conditions using domain knowledge and statistical behavior. A hydraulic circuit was built to measure the delay time experienced from the time the signal is sent to the valve to the time that the valve opens. Experiments were conducted on a three piston in-line digital pump/motor with 2 valves per cylinder, at low and high pressure ports, for a total of six valves. Two high frequency pressure transducers were used in this circuit to measure and analyze the differential pressure on the low and high pressure side of the on/off valves, as well as three in-cylinder pressure transducers. Data over 60 cycles was acquired to analyze the model against real time valve delays. The results show that the algorithm was successful in adapting the threshold for real time valve delays and accurately measuring the valve delays. 

Innovative Minimally Intrusive Sensor Technology Development for Versatile Affordable Advanced Turbine Engine Combustors

2002 ◽  
Author(s):  
Neil Goldstein ◽  
Carlos A. Arana ◽  
Fritz Bien ◽  
Jamine Lee ◽  
John Gruninger ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Real Time ◽  
Gas Turbines ◽  
High Performance ◽  
Chemical Species ◽  
Sensor Technology ◽  
Spectral Signature ◽  
Temperature Pattern ◽  
Hot Gas

The feasibility of an innovative minimally intrusive sensor for monitoring the hot gas stream at the turbine inlet in high performance aircraft gas turbine engines was demonstrated. The sensor uses passive fiber-optical probes and a remote readout device to collect and analyze the spatially resolved spectral signature of the hot gas in the combustor/turbine flowpaths. Advanced information processing techniques are used to extract the average temperature, temperature pattern factor, and chemical composition on a sub-second time scale. Temperatures and flame composition were measured in a variety of combustion systems including a high pressure, high temperature combustion cell. Algorithms for real-time temperature measurements were developed and demonstrated. This approach should provide a real-time temperature profile, temperature pattern factor, and chemical species sensing capability for multi-point monitoring of high temperature and high pressure flow at the combustor exit with application as an engine development diagnostic tool, and ultimately, as a real-time active control component for high performance gas turbines.

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