The article presents a numerical CFD simulation of a throttle-check valve used in an innovative control system for two pneumatic drives. This type of control is used in an innovative rehabilitation device for lower limbs. In order to determine the boundary conditions, experimental tests were carried out. The throttle valves on the test stand were scaled and the air flow rate values were read for different valve opening heights. The purpose of this article is to present a CFD simulation of a pre-adjusted check valve throttle. Numerical simulation (CFD) makes it possible to study the flow phenomena inside a pneumatic throttle-check valve, with different sizes of flow gaps. The obtained results made it possible to determine the distribution of physical quantities of static pressure, the velocity of the medium flowing through the valve, or the vector velocity distribution. The throttle valve assembly has been scaled for a suitable degree of synchronization of the movement of the piston actuators independently of the different external loads acting on each of them. The authors investigated airflow phenomena for different valve opening heights. The simulation provided information on the occurrence of supersonic and subsonic flow velocities at specific valve opening heights.
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http://dx.doi.org/10.1038/s41598-023-29457-4 | DOI Listing |
Medicine (Baltimore)
January 2025
Department of Center for Pulmonary Vascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
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View Article and Find Full Text PDFParasitol Int
January 2025
Morpho-molecular Integration and Technologies Laboratory (LIMT), Institute of Animal Health and Production (ISPA), Federal Rural University of Amazonia (UFRA), Belém, Pará, Brazil. Electronic address:
The present study describes a new myxozoan species, Ellipsomyxa matosi n. sp. infecting the gallbladder of the catfish Ageneiosus ucayalensis, on Jutuba Island, municipality of Belém, state of Pará, Brazil.
View Article and Find Full Text PDFLab Chip
January 2025
Electrical and Computer Engineering, University of Canterbury, 20 Kirkwood Avenue, Ilam, Christchurch, New Zealand.
New flow control elements in capillaric circuits are key to achieving ever more complex lab-on-a-chip functionality while maintaining their autonomous and easy-to-use nature. Capillary field effect transistors valves allow for flow in channels to be restricted and cut off utilising a high pressure triggering channel and occluding air bubble. The reversible capillary field effect transistor presented here provides a new element that can restore fluid flow in closed microchannels autonomous circuit feedback.
View Article and Find Full Text PDFInt J Artif Organs
January 2025
School of Electrical and Information Engineering, Jiangsu University, Zhenjiang, China.
Biventricular assist devices (BiVAD) are capable of providing mechanical support to the left and right ventricles to improve blood supply in heart failure, thereby maintaining patients' lives and improving their quality of life. But there is evidence that the incidence of aortic valve incompetence and other valvular pathologies is related to BiVAD support. Such as constant speed (CS) control may cause the valve to close completely and lose its normal valve function.
View Article and Find Full Text PDFBackground: Significant tricuspid regurgitation (TR) is associated with increased morbidity and mortality. The development of transcatheter valve repair therapies has opened a wide range of opportunities for treatment of patients with high surgical risk. Real-world data might improve patient selection and outcome.
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