GLORIA

GEOMAR Library Ocean Research Information Access

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Online Resource
    Online Resource
    MDPI AG ; 2020
    In:  Energies Vol. 13, No. 18 ( 2020-09-11), p. 4728-
    In: Energies, MDPI AG, Vol. 13, No. 18 ( 2020-09-11), p. 4728-
    Abstract: A water jet is a kind of high-speed dynamic fluid with high energy, which is widely used in the engineering field. In order to analyze the characteristics of the flow field and the change of law of the bottom impact pressure of the oblique submerged impinging jet at different times, its unsteady characteristics at different Reynolds numbers were studied by using the Wray–Agarwal (W-A) turbulence model. It can be seen from the results that in the process of jet movement, the pressure at the peak of velocity on the axis was the smallest, and the velocity, flow angle, and pressure distribution remain unchanged after a certain time. In the free jet region, the velocity, flow angle, and pressure remained unchanged. In the impingement region, the velocity and flow angle decreased rapidly, while the pressure increased rapidly. The maximum pressure coefficient of the impingement plate changed with time and was affected by the Reynolds number, but the distribution trend remained the same. In this paper, the characteristics of the flow field and the law of the impact pressure changing with time are described.
    Type of Medium: Online Resource
    ISSN: 1996-1073
    Language: English
    Publisher: MDPI AG
    Publication Date: 2020
    detail.hit.zdb_id: 2437446-5
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    In: Iranian Journal of Science and Technology, Transactions of Mechanical Engineering, Springer Science and Business Media LLC
    Type of Medium: Online Resource
    ISSN: 2228-6187 , 2364-1835
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2024
    detail.hit.zdb_id: 2843074-8
    SSG: 11
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    Online Resource
    Online Resource
    Elsevier BV ; 2021
    In:  Renewable Energy Vol. 164 ( 2021-02), p. 1029-1038
    In: Renewable Energy, Elsevier BV, Vol. 164 ( 2021-02), p. 1029-1038
    Type of Medium: Online Resource
    ISSN: 0960-1481
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2021
    detail.hit.zdb_id: 2001449-1
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    Online Resource
    Online Resource
    MDPI AG ; 2019
    In:  Processes Vol. 7, No. 12 ( 2019-12-03), p. 915-
    In: Processes, MDPI AG, Vol. 7, No. 12 ( 2019-12-03), p. 915-
    Abstract: As an important over-current component of the waterjet propulsion system, the main function of a nozzle is to transform the mechanical energy of the propulsion pump into the kinetic energy of the water and eject the water flow to obtain thrust. In this study, the nozzle with different geometry and parameters was simulated based on computational fluid dynamics simulation and experiment. Numerical results show a good agreement with experimental results. The results show that the nozzle with a circular shape outlet shrinks evenly. Under the designed flow rate condition, the velocity uniformity of the circular nozzle is 0.26% and 0.34% higher than that of the elliptical nozzle and the rounded rectangle nozzle, respectively. The pump efficiency of the circular nozzle is 0.31% and 0.14% higher than that of the others. The pressure recovery and hydraulic loss of the circular nozzle are superior. The hydraulic characteristics of the propulsion pump and waterjet propulsion system are optimal when the nozzle area is 30% times the outlet area of the inlet duct. Thus, the shaft power, head, thrust, and system efficiency of the propulsion pump and waterjet propulsion system are maximized. The system efficiency curve decreases rapidly when the outlet area exceeds 30% times the outlet area of the inlet duct. The transition curve forms greatly affect thrust and system efficiency. The transition of the linear contraction shows improved uniformity, and the hydraulic loss is reduced. Furthermore, the hydraulic performance of the nozzle with a linear contraction transition is better than that of others.
    Type of Medium: Online Resource
    ISSN: 2227-9717
    Language: English
    Publisher: MDPI AG
    Publication Date: 2019
    detail.hit.zdb_id: 2720994-5
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    In: Agriculture, MDPI AG, Vol. 12, No. 11 ( 2022-10-25), p. 1770-
    Abstract: The pumping station is an important part of the agricultural irrigation and drainage system. The sump is one of the common water inlet types of agricultural pumping stations. In the sump, to facilitate the installation and maintenance of equipment, some hydraulic structures, such as pump beams, maintenance platforms and chest walls, are added to the sump. At present, the impact of hydraulic structures in the sump on the hydraulic performance of the pump device is not clear, so this paper focused on the impact of hydraulic structures on the hydraulic characteristics and entropy generation characteristics of the pump device by using numerical simulation methods. The results showed that the installation of hydraulic structures in the sump has the greatest impact on the efficiency of the pump device. The efficiency coefficient increased after adding a pump beam in the sump and decreased by about 2% after adding a maintenance platform and a water retaining chest wall. Results also showed that the installation of hydraulic structures in the sump will lead to uneven distribution of entropy generation in the sump, especially in the vicinity of the hydraulic structures. The installation of the maintenance platform and chest wall will lead to the increase of the total entropy generation in the sump, which also means that the hydraulic loss in the sump will increase accordingly. Hence, in addition to the pump beam, other structures should be avoided in the sump.
    Type of Medium: Online Resource
    ISSN: 2077-0472
    Language: English
    Publisher: MDPI AG
    Publication Date: 2022
    detail.hit.zdb_id: 2651678-0
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 6
    Online Resource
    Online Resource
    Frontiers Media SA ; 2023
    In:  Frontiers in Energy Research Vol. 11 ( 2023-4-13)
    In: Frontiers in Energy Research, Frontiers Media SA, Vol. 11 ( 2023-4-13)
    Abstract: To study the internal flow characteristics and energy characteristics of a large bulb perfusion pump. Based on the CFX software of the ANSYS platform, the steady calculation of the three-dimensional model of the pump device is carried out. The numerical simulation results obtained by SST k-ω and RNG k-ε turbulence models are compared with the experimental results. Finally, SST k-ω is selected for subsequent calculation. With the help of the flow line diagram and turbulent kinetic energy table of the whole flow channel of the pump device, the flow components of the pump device under different working conditions are analyzed, and the pressure and velocity distribution at the impeller and guide vane are analyzed by pressure cloud diagram and velocity cloud diagram. It is found that there are three high-pressure areas in the impeller and guide vane section, and the high-pressure regions are mainly distributed in the middle of the impeller channel. As the head decreases, the pressure at the impeller and guide vane positions decreases gradually, and the flow rate increases. Based on the entropy production principle, the wall entropy production and the distribution of mainstream entropy production at the impeller and guide vane parts are analyzed.
    Type of Medium: Online Resource
    ISSN: 2296-598X
    Language: Unknown
    Publisher: Frontiers Media SA
    Publication Date: 2023
    detail.hit.zdb_id: 2733788-1
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 7
    Online Resource
    Online Resource
    SAGE Publications ; 2024
    In:  Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy Vol. 238, No. 4 ( 2024-06), p. 633-647
    In: Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy, SAGE Publications, Vol. 238, No. 4 ( 2024-06), p. 633-647
    Abstract: In order to improve the operation efficiency of low-head tubular pump, this paper studies the influence of shaft type in the shaft tubular pump on the flow characteristics and energy characteristics of the pump. To optimize the shaft structure of shaft tubular pumping systems and realize the efficient use of energy, numerical simulation and model test was employed to study the optimization of the entire pumping system. In this paper, the CFD method was used to numerically simulate the whole pumping system, and the effect of changing the shaft length, shaft head profile, and shaft tail profile on the internal flow and entropy production characteristics of the inlet passage and impeller position were analyzed. It is found that the tapered tail profile can make the inlet passage overflow area change more smoothly and thus make the flow pattern more favorable. The wall entropy production dissipation at the inlet passage position dominates the total entropy production, and the high-value area of mainstream entropy production at this position is distributed periodically. The mainstream entropy production dissipation at the impeller section accounts for a relatively large proportion. After the entropy production dissipation analysis, it is believed that the tapered can reduce the entropy production dissipation of the pumping systems. The change of the shaft tail profile will make the entropy production dissipation change more noticeable compared with other optimization factors. Therefore, the tapered tail profile with better transition in the actual project is recommended.
    Type of Medium: Online Resource
    ISSN: 0957-6509 , 2041-2967
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2024
    detail.hit.zdb_id: 2024892-1
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 8
    In: Energy Reports, Elsevier BV, Vol. 9 ( 2023-12), p. 2075-2086
    Type of Medium: Online Resource
    ISSN: 2352-4847
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2023
    detail.hit.zdb_id: 2814795-9
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 9
    In: Ocean Engineering, Elsevier BV, Vol. 268 ( 2023-01), p. 113429-
    Type of Medium: Online Resource
    ISSN: 0029-8018
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2023
    detail.hit.zdb_id: 1498543-3
    detail.hit.zdb_id: 160791-1
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 10
    Online Resource
    Online Resource
    Hindawi Limited ; 2019
    In:  Advances in Materials Science and Engineering Vol. 2019 ( 2019-10-24), p. 1-21
    In: Advances in Materials Science and Engineering, Hindawi Limited, Vol. 2019 ( 2019-10-24), p. 1-21
    Abstract: As an important overcurrent component in a waterjet propulsion system, the inlet passage is used to connect the propulsion pump and the bottom of the propulsion ship. The anticavitation, vibration, and noise performance of the waterjet propulsion pump are significantly affected by the hydraulic performance of the inlet passage. The hydraulic performance of the inlet passage directly affects the overall performance of the waterjet propulsion system, thus the design and optimization method of the inlet passage is an important part of the hydraulic optimization of the waterjet propulsion system. In this study, the hydraulic characteristics of the inlet passage in the waterjet propulsion system with different flow parameters and geometric parameters were studied by a combination of numerical simulation and experimental verification. The model test was used to verify the hydraulic characteristics of the waterjet propulsion system, and the results show that the numerical results are in good agreement with the test results. The numerical results are reliable. The hydraulic performance of the inlet passage is significantly affected by the inlet velocity ratio. There is a certain correlation between the hydraulic performance of the inlet passage and ship speed, and the hydraulic performance of the inlet passage is limited by ship speed. The geometric parameters of the best optimization case are as follows: the inflow dip angle α is 35°, the length L is 6.38 D 0 , and the upper lip angle is 4°. The optimal operating conditions are the conditions of IVR 0.69–0.87.
    Type of Medium: Online Resource
    ISSN: 1687-8434 , 1687-8442
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2019
    detail.hit.zdb_id: 2501025-6
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...