Computational modeling of hydrogen behavior and thermo-pressure dynamics for safety assessment in nuclear power plants DOI
Joseph Amponsah, Emmanuel Adorkor, David Ohene Adjei Opoku

et al.

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(12)

Published: Dec. 1, 2024

Following the Three Mile Island Nuclear Generating Station incident 1979, extensive research has focused on preventing hydrogen accumulation and explosions during nuclear power plant emergencies. We used advanced computational fluid dynamics (CFD) simulations to analyze distribution, pressure dynamics, efficacy of safety measures across various containment structures under accident scenarios. Results indicate that smaller experience rapid accumulation, reaching a peak 2.5 bars temperature 120 °C within first 30 s. Structural integrity is compromised at pressures around 3.8 bars, leading failure 10 min sustained high pressure. In contrast, larger exhibit delayed buildup, peaking 2.3 with corresponding 110 °C, maintain for up min. Fire scenarios demonstrate reach temperatures 500 which resulted in partial structural failure, whereas containments withstand 450 40 without compromise. When concentrations exceed 35%, surpass 1430 explosion risks increase substantially, reduces effectiveness passive mitigation systems.

Language: Английский

Influence of dielectric characteristics on bubble dynamics and material removal mechanism in electrical discharge machining DOI

Weiye Peng,

Jiajing Tang, Zhengkai Li

et al.

Physics of Fluids, Journal Year: 2025, Volume and Issue: 37(1)

Published: Jan. 1, 2025

The bubble formation process during electrical discharge machining (EDM) is affected by the dielectric and magnitude of flow rate. At present, dynamic characteristics material removal are insufficiently characterized in existing studies. In this study, processes workpiece were simulated based on model flushing three-phase for EDM with different dielectrics rates, pressure, characteristics, mechanism analyzed. Meanwhile, rate experiments single pulse de-ionized water carried out to verify above liquid. These results showed that both debris accumulation effect can delay explosion impacting pressure. degree expansion volume molten fluid determine size region together. weakening impact promotes stable growth while decreasing contribution higher than bubble, 80% discharged through enhancing flushing. There more frequent evolution behaviors dynamics emulsion a period kerosene. study these revealed detailed understanding system EDM, providing foundation improvement efficiency quality.

Language: Английский

Citations

0
Dynamics of a tail cavity induced by the vertical motion of an underwater vehicle DOI
J. L. Liu, Wei Xiao, Xiongliang Yao

et al.

Physics of Fluids, Journal Year: 2025, Volume and Issue: 37(2)

Published: Feb. 1, 2025

This study investigates the dynamics of tail cavity induced by an underwater vehicle. The morphological evolution and pressure characteristics are simulated using a numerical model based on boundary integral method. is validated against experiments conducted us. mechanisms certain behaviors during process explored from perspective pressure, flow field at different vertical radial positions obtained. Then, influence initial vehicle velocity parameter fracture jet studied. In terms behavior, we find that location length sub-cavities undergo abrupt changes as vary. secondary necking considered primary cause these changes. jetting governing parameters impact collapse extent moment impact. Finally, variation kinetic energy attached sub-cavity residual this quantitatively studied within selected space.

Language: Английский

Citations

0
Thermal and mechanical attributes and swelling percentage of hydrogels by changing in magnetic field frequency using computer simulation DOI
Haoyu Wang, Ali Basem, Sabah F. H. Alhamdi

et al.

International Communications in Heat and Mass Transfer, Journal Year: 2025, Volume and Issue: 165, P. 109070 - 109070

Published: May 11, 2025

Language: Английский

Citations

0
Study on the effect of geometric shape on microswimmer upstream motion DOI
Siwen Li, Deming Nie

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(10)

Published: Oct. 1, 2024

The upstream motility of three microswimmer shapes (circular squirmer, squirmer rod, and elliptical squirmer) at the center a Poiseuille flow is numerically investigated using lattice Boltzmann method. Based on stability ability, swimming velocities four motion states (stable motion, progressively unstable failure) are summarized. results show that circular rod more stable than squirmer; however, has greatest advantage in velocity can swim up to twice as fast under same conditions. type also key influencing state, which reflected differently distinct shapes. increase Reynolds number (Re) self-propelled strength (α) aggravates instability; for elongated microswimmers, aspect ratio (ε) plays role rather state. Moreover, pusher always better puller, especially when Re increases. Notably, all microswimmers maintain preset maximum field. These findings provide guidelines selection design parameters appearance resist complex incoming flows.

Language: Английский

Citations

2
Computational modeling of hydrogen behavior and thermo-pressure dynamics for safety assessment in nuclear power plants DOI
Joseph Amponsah, Emmanuel Adorkor, David Ohene Adjei Opoku

et al.

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(12)

Published: Dec. 1, 2024

Following the Three Mile Island Nuclear Generating Station incident 1979, extensive research has focused on preventing hydrogen accumulation and explosions during nuclear power plant emergencies. We used advanced computational fluid dynamics (CFD) simulations to analyze distribution, pressure dynamics, efficacy of safety measures across various containment structures under accident scenarios. Results indicate that smaller experience rapid accumulation, reaching a peak 2.5 bars temperature 120 °C within first 30 s. Structural integrity is compromised at pressures around 3.8 bars, leading failure 10 min sustained high pressure. In contrast, larger exhibit delayed buildup, peaking 2.3 with corresponding 110 °C, maintain for up min. Fire scenarios demonstrate reach temperatures 500 which resulted in partial structural failure, whereas containments withstand 450 40 without compromise. When concentrations exceed 35%, surpass 1430 explosion risks increase substantially, reduces effectiveness passive mitigation systems.

Language: Английский

Citations

0