Investigation effects of roughness in wet steam flow with Buckingham Pi-theorem

Salmani, Fahime; Mahpeykar, Mohammad Reza

doi:10.1007/s10973-020-10526-z

Cited by 14 publications

(6 citation statements)

References 34 publications

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“…Sinha et al (2009) used it to simulate the steam flow in a supersonic nozzle. Salmani et al (2022) also investigated the effect of surface roughness on the simulation of the wet steam flow using Hale's nucleation equation.…”

Section: Introductionmentioning

confidence: 99%

The search for an appropriate condensation model to simulate wet steam transonic flows

Lakzian

Ramezani

Shabani

et al. 2023

HFF

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Purpose The purpose of this study is to model steam condensing flows through steam turbine blades and find the most suitable condensation model to predict the condensation phenomenon. Design/methodology/approach To find the most suitable condensation model, five nucleation equations and four droplet growth equations are combined, and 20 cases are considered for modelling the wet steam flow through steam turbine blades. Finally, by the comparison between the numerical results and experiments, the most suitable case is proposed. To find out whether the proposed case is also valid for other boundary conditions and geometries, it is used to simulate wet steam flows in de Laval nozzles. Findings The results indicate that among all the cases, combining the Hale nucleation equation with the Gyarmathy droplet growth equation results in the smallest error in the simulation of wet steam flows through steam turbine blades. Compared with experimental data, the proposed model’s relative error for the static pressure distribution on the blade suction and pressure sides is 2.7% and 2.3%, respectively, and for the liquid droplet radius distribution it totals to 1%. This case is also reliable for simulating condensing steam flows in de Laval nozzles. Originality/value The selection of an appropriate condensation model plays a vital role in the simulation of wet steam flows. Considering that the results of numerical studies on condensation models in recent years have not been completely consistent with the experiments and that there are still uncertainties in this field, further studies aiming to improve condensation models are of particular importance. As condensation models play an important role in simulating the condensation phenomenon, this research can help other researchers to better understand the purpose and importance of choosing a suitable condensation model in improving the results. This study is a significant step to improve the existing condensation models and it can help other researchers to gain a revealing insight into choosing an appropriate condensation model for their simulations.

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Section: Introductionmentioning

confidence: 99%

The search for an appropriate condensation model to simulate wet steam transonic flows

Lakzian

Ramezani

Shabani

et al. 2023

HFF

Self Cite

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“…24 The backpressure change on the two-phase flow in a turbine cascade was investigated by Nikkhahi et al 25 The results indicated that the condensation decreases by reducing downstream pressure on the suction walls of the turbine. The simultaneous effect of roughness pressure for two-phase supersonic steam flows through a divergent-convergent nozzle was studied with Buckingham Pi-theorem by Salmani et al 26 For numerical modeling of the rotor-stator interactions, different techniques including mixing plan, 27 sliding mesh, 28 and the frozen rotor, 29 have been considered. Frozen rotor is an optional setting for rotating analyses that reduces simulation time and produces an approximate solution.…”

Section: Introductionmentioning

confidence: 99%

“…24 The back-pressure change on the two-phase flow in a turbine cascade was investigated by Nikkhahi et al 25 The results indicated that the condensation decreases by reducing downstream pressure on the suction walls of the turbine. The simultaneous effect of roughness pressure for two-phase supersonic steam flows through a divergent-convergent nozzle was studied with Buckingham Pi-theorem by Salmani et al 26…”

Section: Introductionmentioning

confidence: 99%

Enhancing low-pressure stage steam turbine using the TDLD criterion and the TOPSIS analysis

Dolatabadi,

Lakzian,

Masoumi

et al. 2023

Proceedings of the Institution of Mechanical Engineers, Part C:

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The liquid phase in the wet steam flow causes thermodynamics losses and affects steam turbine blade durability. The main objective of the present research is the design of the rotor stagger angle and different operating conditions in the low-pressure stage of the steam turbine. A two-phase Eulerian-Eulerian model and the SST k − ω model are used to simulate the viscous wet steam flow inside the steam turbine stage. Frozen rotor methodology is employed for modeling the stator-rotor interaction. The effects of different rotor stagger angles and different outlet pressure levels on the wet steam flow parameters are studied to introduce an improved case. The turbine stage efficiency, droplet average radius, liquid mass fraction, and degree of reaction (TDLD) are considered as design criteria. The search for the improved value of pressure ratio and rotor stagger angle is performed using the TDLD criterion by TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution). The improved case is selected with a rotor stagger angle of 64 degrees and outlet pressure of 6.5 kPa, at which the turbine stage efficiency (TSE) is increased by 21.3% compared to [Formula: see text]. Also, the liquid mass fraction (LMF) and the degree of reaction (DOR) reduced by 39.53 and 26% relative to [Formula: see text], and [Formula: see text], respectively. In addition, droplet average radius (DAR) increases by 26.14% compared to [Formula: see text].

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“…Therefore, the combination of experiment and computational fluid dynamics by non-contact PIV technology can fully reveal the internal flow and energy loss law of RCP, provide ideas and theoretical support for the design and development of efficient and stable RCP. In addition, the roughness effect [30] should be paid attention to when studying RCP. This paper studies the energy performance and internal flow characteristics under main operating conditions on the basis of non-contact measurement in the RCP.…”

Section: Introductionmentioning

confidence: 99%

Experimental Study on PIV Measurement and CFD Investigation of the Internal Flow Characteristics in a Reactor Coolant Pump

Lu²,

Huang

et al. 2023

Energies

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The nuclear reactor coolant pump (RCP) is the core piece of equipment of a nuclear power plant (NPP). The energy performance and internal flow characteristics of RCPs are revealed by effective measurement methods, which are helpful to understand the flow mechanism of RCPs. The present work is intended to conduct an integrated study based on the energy performance test and Particle Image Velocimetry (PIV) flow-field non-contact measurement of the RCP. In addition, the prediction results of different turbulence models are compared with experimental results in detail. Through energy performance measurement and numerical calculation analysis, it can be found that various turbulence models have the ability to predict the performance of RCPs in engineering applications. At 0.8~1.2 Φd operating conditions, the maximum error is less than 10% and the minimum error is less than 0.1% by analyzing the energy performance of numerical calculations and experimental results. The PIV results show that the velocity of the discharge nozzle varies greatly from right (outlet of diffuser channel 2) to left (outlet of diffuser channel 12) due to different flow structures. Through the qualitative and quantitative comparison of the internal flow field, it can be concluded that, except for the low flow rate, compared with other computational models, the Realizable k-ε model can better predict the internal flow field of an RCP. The reasons for the experimental error and numerical calculation error are analyzed in detail, and the results can provide a reference for forecasting an RCP internal flow field with a special and complex structure.

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Investigation effects of roughness in wet steam flow with Buckingham Pi-theorem

Cited by 14 publications

References 34 publications

The search for an appropriate condensation model to simulate wet steam transonic flows

The search for an appropriate condensation model to simulate wet steam transonic flows

Enhancing low-pressure stage steam turbine using the TDLD criterion and the TOPSIS analysis

Experimental Study on PIV Measurement and CFD Investigation of the Internal Flow Characteristics in a Reactor Coolant Pump

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