Wyniki wyszukiwania - Biblioteka Nauki

Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl

Ograniczanie wyników

Znaleziono wyników: 4

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: prędkość strumienia

Sortuj według:

Ogranicz wyniki do:

Rola prędkości strumienia w procesach formowania powłok metodą detonacyjną

100%

Babul T.

Przegląd Spawalnictwa

2006

tom R. 78, nr 12

4-6

Omówiono wpływ wybranych parametrów technologicznych na prędkość ziaren proszku gatunku NiCrBSi nanoszonych metodą detonacyjną. Pokazano sposoby umożliwiające zwiększenie prędkości strumienia przy zachowaniu identycznych parametrów ciśnienia i proporcji gazów roboczych. Zwrócono uwagę na możliwości kształtowania struktury materiału podłoża oraz przenikania materiału powłoki w podłoże w zależności od prędkości strumienia metalizacyjnego.

Influence ot selected technological parameters on powder grain speed of NiCrBSi grade applied by means of the d-gun spraying method was discussed. The methods making it possible to increase stream speed while maintaining identical parameters of pressure and proportion of working gases were presented. Attention was drawn to the possibility to shape substrate material structure and coating material penetration into the substrate depending on the metallization stream speed.

Analiza metod pomiaru rozkładu prędkości strumieni powietrza w kabinach lakierniczych

75%

Nikończuk P. , Królikowski T. , Rypina Ł.

tom R. 22, nr 12

1108--1111, CD

W artykule przedstawiono analizę metod pomiaru rozkładu prędkości strumieni powietrza w pomieszczeniach. Analiza koncentruje się na przykładzie kabin lakierniczych, ze względu na charakter procesu lakierniczego wymagana jest wymiana powietrza z utrzymaniem odpowiednich reżimów. Oprócz analizy istniejących metod przedstawiono koncepcyjną metodę pomiaru wykorzystującą obrazy termowizyjne. Wyniki pomiarów pozwalają również na weryfikację numerycznych modeli CFD obrazujących obieg powietrza w modelowanych pomieszczeniach.

The paper presents analysis of current measurement methods of air streams distribution inside closed spaces. Analysis is focused on measurement inside spray booths. In case of specific nature of finishing process the air exchange in workspace is obligatory. The quality of air exchange is regulated with many requirements including air balance. Measurement will also help to verify numerical CFD models of air streams distribution.

Flow structure investigation over a pool-rife sequence in a variable width river

63%

Tabarestani E. S. , Afzalimehr H. , Pham Q. B.

Acta Geophysica

2022

tom Vol. 70, no 2

713--727

A comprehensive overview of flow characteristics in natural channels with bedforms is a vital issue in river management projects. Pool-rife sequences as common bedforms in the gravel-bed rivers significantly impact flow characteristics and turbulence intensity. The present study was taken by field investigation in the Babolroud River, Iran. A 95 m reach with variable width was chosen in this river and velocity components and shear stress were obtained in different sections. Quadrant analysis was also applied to determine the dominant bursting event in the pool section. The results revealed a phase shift for stream-wise velocity, near-bed velocities, and bed shear stress versus bed profile. In the pool, vertical velocity components were oriented downward near the bed and upward near the water surface, while in the rife section vectors were oriented towards the bed. The findings of quadrant analysis demonstrated the ejections and sweeps as a dominant event close to the bed and water surface, respectively.

Modelling the dynamics of microbubble undergoing stable and inertial cavitation: Delineating the effects of ultrasound and microbubble parameters on sonothrombolysis

63%

Tan Z. Q. , Ooi E. H. , Chiew Y. S. , Foo J. J. , Ng Y. K. , Ooi E. T.

Biocybernetics and Biomedical Engineering

2024

tom Vol. 44, no. 2

358--368

Sonothrombolysis induces clot breakdown using ultrasound waves to excite microbubbles. Despite the great potential, selecting optimal ultrasound (frequency and pressure) and microbubble (radius) parameters remains a challenge. To address this, a computational model was developed to investigate the bubble behaviour during sonothrombolysis. The blood and clot were assumed to be non-Newtonian and porous, respectively. The effects of ultrasound and microbubble parameters on flow-induced shear stress on the clot surface during stable and inertial cavitation were investigated. It was found that microbubble translation towards the clot and the shear stress on the clot surface during stable cavitation were significant when the bubble was about to undergo inertial cavitation. While insonation of large microbubble (radius of 1.65 μm) at low frequency (0.50 MHz) produced the highest shear stress during stable cavitation, selection of these parameters is not as intuitive for inertial cavitation due to the strong competing effect between jet velocity and translational distance. An increase in jet velocity is always accompanied by a decrease in the translational distance and vice versa. Therefore, a right balance between the jet velocity and the translational distance is critical to maximise the shear stress on the clot surface. A jet velocity of 303 m/s and a distance travelled of 5.12 μm at an initial bubble-clot separation of 10 μm produced the greatest clot surface shear stress. This is achievable by insonating a 0.55 μm microbubble using 0.50 MHz and 600 kPa ultrasound.