Micro-Pneumatic Logic

2004 ◽  
Author(s):  
Albert K. Henning
Keyword(s):  
Mechanical Behavior ◽  
Flow Behavior ◽  
Control Device ◽  
Signal Frequency ◽  
Silicon Membrane ◽  
Qualitative Comparison ◽  
Flow Control Device ◽  
Model Equations ◽  
Rigorous Model ◽  
Saturation Flow

Advances in silicon membrane and microvalve technology continue to be made. Microvalves utilizing membranes have always encompassed the attribute of an on-off switch, thereby suggesting a logic element, although their main application has been arguably as a proportional flow control device. Recently, an analogy has been suggested between a microelectronic, p-channel MOSFET, and a microvalve. The analogy includes a qualitative comparison between the flow vs. pressure relationship for the microvalve, and the current vs. voltage relationship for the MOSFET. It also includes a simple, small-signal frequency analysis of microvalve flow, based on a ‘saturation’ flow behavior chosen arbitrarily to be similar to that in a MOSFET. In this work, a quantitative and rigorous model for the flow vs. pressure relationship for a microvalve is presented. The model couples the mechanical behavior of a silicon membrane, with the fluid mechanical behavior facilitated by the membrane’s motion. The model is substantiated by measurements. The model is compared by analogy to the related MOSFET model equations. The pneumatic model is then applied to both a normally-closed microvalve, and a normally-closed poppet valve. The normally-closed microvalve is analogous to a p-MOSFET. The normally-closed poppet microvalve is analogous to an n-MOSFET. By appropriate physical coupling of these two devices, a fully complementary pneumatic NOR gate results. The quantitative pneumatic flow model is applied to this structure, and the logic transfer function is obtained. The ramifications of the results for scaled, micro-pneumatic logic devices will be discussed.

Sound suppressing gas flow control device

1980 ◽  
Vol 67 (4) ◽  
pp. 1413-1413
Author(s):  
George J. Kay ◽  
Alan Keskimen
Keyword(s):  
Flow Control ◽  
Gas Flow ◽  
Control Device ◽  
Flow Control Device

Design, Development, and Characterization of a Flow Control Device for Dynamic Cooling of Liquid-Cooled Servers

2021 ◽  
Author(s):  
Pardeep Shahi ◽  
Apurv Deshmukh ◽  
Hardik Hurnekar ◽  
Satyam Saini ◽  
Pratik V Bansode ◽  
...  
Keyword(s):  
Thermal Management ◽  
Flow Rate ◽  
Control Device ◽  
Servo Motor ◽  
Pumping Power ◽  
Liquid Cooling ◽  
Flow Rates ◽  
Flow Control Device ◽  
Dynamic Cooling ◽  
Valve Position

Abstract Transistor density trends till recently have been following Moore's law, doubling every generation resulting in increased power density. The computational performance gains with the breakdown of Moore's law were achieved by using multi-core processors, leading to non-uniform power distribution and localized high temperatures making thermal management even more challenging. Cold plate-based liquid cooling has proven to be one of the most efficient technologies in overcoming these thermal management issues. Traditional liquid-cooled data center deployments provide a constant flow rate to servers irrespective of the workload, leading to excessive consumption of coolant pumping power. Therefore, a further enhancement in the efficiency of implementation of liquid cooling in data centers is possible. The present investigation proposes the implementation of dynamic cooling using an active flow control device to regulate the coolant flow rates at the server level. This device can aid in pumping power savings by controlling the flow rates based on server utilization. The FCD design contains a V-cut ball valve connected to a micro servo motor used for varying the device valve angle. The valve position was varied to change the flow rate through the valve by servo motor actuation based on pre-decided rotational angles. The device operation was characterized by quantifying the flow rates and pressure drop across the device by changing the valve position using both CFD and experiments. The proposed FCD was able to vary the flow rate between 0.09 lpm to 4 lpm at different valve positions.

scholarly journals Heat and mass transfer in a metal hydride reactor: combining experiments and mathematical modelling

2021 ◽  
Vol 2057 (1) ◽  
pp. 012122
Author(s):  
D O Dunikov ◽  
V I Borzenko ◽  
D V Blinov ◽  
A N Kazakov ◽  
I A Romanov ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Mass Flow ◽  
Metal Hydride ◽  
Porous Metal ◽  
Control Device ◽  
Variable Permeability ◽  
Flow Control Device ◽  
Porous Domain

Abstract Heat transfer in porous metal hydride (MH) beds determines efficiency of MH devices. We present a COMSOL Multiphysics numerical model and experimental investigation of heat and mass transfer in a MH reactor filled with 4.69 kg of AB5 type alloy (Mm0.8La0.2Ni4.1Fe0.8Al0.1). To achieve an agreement between the model and experiments it is necessary to include a flow control device (inlet valve or flow regulator) into the model. We propose a simplified and easy-to-calculate boundary condition based on a porous domain with variable permeability at reactor inlet. The permeability of the domain is connected with hydrogen mass flow by a PID controller. Thus, boundary conditions for the inlet pressure and mass flow are coupled and heat transfer inside the reactor could be calculated without additional assumptions applied to heat and mass transfer in the MH bed.

The Development of a Pressure Actuated Isolation Nozzle Assembly and its Application as Flow Control Device in Extended Reach Water-Alternating-Gas Pilot Wells

2021 ◽  
Author(s):  
Zhihua Wang ◽  
Aqib Qureshi ◽  
Tarik A Abdelfattah ◽  
Joshua R Snitkoff
Keyword(s):  
Flow Control ◽  
Drilling Fluid ◽  
Applied Pressure ◽  
Control Device ◽  
Lessons Learned ◽  
Production Performance ◽  
Dissolution Time ◽  
Enhanced Production ◽  
Water Alternating Gas ◽  
Flow Control Device

Abstract The re-development of a giant offshore field in the United Arab Emirates (UAE) consists predominantly of four artificial islands requiring in most cases extremely long horizontal laterals to reach the reservoir targets. Earlier SPE technical papers (1,2) have introduced the development, testing, qualification, and deployment of the plugged liner technology using the dissolvable plugged nozzles (DPNs). The use of DPN plugged liner technology has resulted in CAPEX savings and enhanced production performance. The benefits of DPN technology are its simplicity along with its cost effectiveness. However, the dissolvable material has some limitations, such as pressure rating and dissolution time, which are fluid chemistry dependent. To overcome these limits, a new Pressure Actuated Isolation Nozzle Assembly (PAINA) was developed as an alternative to the plugged liner tool for applications where a higher pressure rating is required, as well as on demand opening. Furthermore, the new PAINA also functions as a flow control device during injection and production, enhancing acid jetting effects during bullhead stimulation and reducing brine losses during liner installation. Liners with PAINAs can be run to TD similar to blank pipe: fluids can be circulated through the inside of the liner without the need for a wash pipe. Once on bottom, non-aqueous drilling fluid is displaced to brine without actuating the isolation mechanism. When the well is ready for production or injection, pressure is applied and the isolation mechanism is activated to establish communication between well and reservoir. These tools were successfully run as flow control devices in water-alternating-gas (WAG) pilot wells. The planning and execution of the initial application will be discussed, along with the tool development, qualification testing, and lessons learned. The key advantage of this technology is in extending plugged liner applications to cases where other pressure-operated tools are included as part of the liner lower completion. Pressure can be applied to the well multiple times without activating the isolation mechanism as long as the applied pressure is below the actuation pressure.

Investigation of a Passive Flow Control Device in an S-Duct Inlet of a Propulsion System With High Subsonic Flow

2018 ◽  
Author(s):  
Asad Asghar ◽  
Satpreet Sidhu ◽  
William D. E. Allan ◽  
Grant Ingram ◽  
Tom M. Hickling ◽  
...  
Keyword(s):  
Flow Control ◽  
Complex Geometry ◽  
Control Device ◽  
Pressure Recovery ◽  
Passive Flow Control ◽  
Passive Flow ◽  
Flow Control Device ◽  
Inner Radius ◽  
Selection Of ◽  
Numerical Approaches

S-Ducts have wide application on air vehicles with embedded engines. The complex geometry is known to lead to separation downstream of curved profiles. This paper reports the influences on that flow of passive flow control geometries. In these experiments, stream-wise tubercles were applied in an effort to improve the internal performance of S-duct diffusers, parameters including pressure recovery, distortion and swirl. The test articles were tested with the high subsonic (Ma = 0.8) flow and were manufactured using 3D printing. Stream-wise static pressure and exit-plane total pressure were measured in a test rig using surface pressure taps and a 5-probe rotating rake, respectively; the baseline and variant S-ducts were simulated through computational fluid dynamics. The experiments showed that some subtle improvements to the S-Duct distortion could be achieved through careful selection of tubercle geometry. Generally, the recovered flow downstream of the inner radius of the second bend of the S-duct deteriorated, but overall pressure recovery improved. The simulations were useful in characterizing swirl, whereas experiments were not so equipped. Adjustments to the numerical approaches resulted in reasonable agreement with the experiments.

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