Numerical evaluation on the decaying swirling flow in a multi-lobed swirl generator

Yan, Tie; Qu, Jingyu; Sun, Xiaofeng; Chen, Ye; Hu, Qiaobo; Li, Wei

doi:10.1080/19942060.2020.1816494

Cited by 8 publications

(3 citation statements)

References 30 publications

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“…The Reynolds stress model (RSM) was used to solve transport equations, incorporating individual Reynolds stresses < 𝑢 𝑖 ′ 𝑢 𝑖 ′ > to predict the turbulence characteristics downstream of the TDWS. Because the RSM is more refined than any other Reynolds Average Navier-Stokes (RANS) model, Yan et al, [33] also used RSM for the numerical evaluation of a decaying multi-lobed swirl generator in a plain horizontal tube.…”

Section: Continuity Equationmentioning

confidence: 99%

Thermo-Hydraulic Performance of Heated Tube with Twisted Delta Winglet Swirler Insert: A Numerical Simulation

Amin

Azmi

Ismail

2022

ARFMTS

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Among the various methods for enhancing heat transfer in a heat exchanger, a passive method of inserting a continuous swirler inside a heated tube provides a secondary flow along the fluid that reduces the thickness of the thermal boundary layer, thus increasing the efficiency of convection heat transfer performance. The research’s primary goal is to conserve energy, materials, and money by operating efficient heat exchanger equipment. However, the continuous swirler along the fluid flow creates a persistent obstruction, which amplifies the friction factor and increases the working fluid’s energy loss. As a result, this research presented the twisted delta winglet swirler (TDWS), a new design of a decaying swirler that uses delta winglets twisted to 180° to produce a swirling flow along the tube. The swirler comprises four twisted delta winglets arranged in a circle with a diameter 6% smaller than the tube and a length of L/D=2.2. It was placed at the entrance to a heated tube test section with a diameter of 0.016 m and a length of L/D=93.75. The Reynolds Stress Model was used to simulate the flow domain with a water-ethylene glycol mixture was chosen as the working fluid. TDWS transformed the uniform inlet flow from potential energy to high kinetic energy, resulting in a high intensity of swirling flow downstream of the circular tube up to L/D=46.88 before decaying and reaching a steady state. Compared to other decaying swirlers, TDWS obtained one of the lowest relative friction factors, 1.36, with this flow. The maximum global relative Nusselt number increased by only 11% because this value considered the area where the flow reached a steady state. Since the TDWS is a decaying swirler, the thermal-hydraulic performance reached unity along the tube. However, the optimal performance of TDWS in the plain tube with a length of L/D=93.75 can be found if the dimension or geometric configuration of the TDWS is modified, or two or more TDWS may be placed in an array orientation.

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Section: Continuity Equationmentioning

confidence: 99%

Thermo-Hydraulic Performance of Heated Tube with Twisted Delta Winglet Swirler Insert: A Numerical Simulation

Amin

Azmi

Ismail

2022

ARFMTS

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“…The first application of the combined CFD-DEM model was reported to be the solid particle plug flow in a horizontal tube 16 , and then many others have been devoted to the analysis and simulation of various aspects of fluidized beds using coupled CFD-DEM calculations 17 . In the coupled solution process, the flow field is treated as a continuous phase and the solid phase is treated as a discrete phase, and the corresponding solutions for the flow field and the particle phase are obtained by the coupled calculation of the two software [18][19][20] .…”

Section: And Zhenfeng Jiangmentioning

confidence: 99%

Analysis of gas–solid two-phase flow and structure optimization of mobile shot blasting machine recovery device

Zhang

Men

et al. 2022

Sci Rep

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To address the problem of low efficiency of recycling process waste by gas–solid two-phase flow of the shot blasting machine recycling device, a method and structure by increasing the negative pressure value and optimizing the outlet pipe position are proposed. Computational fluid dynamics (CFD), discrete element method (DEM) and discrete phase model (DPM) were used to study the waste recovery efficiency at different pressure outlet conditions and outlet pipe locations. The validity of the model was verified by velocity tests at the outlet and inlet compared with simulations. The effect of particle size and particle generation rate on solid particle recovery efficiency was further investigated by analyzing the flow field distribution of the recovery unit. The results show that the maximum velocity of the gas phase in the recovery device increases with the increase of the absolute value of the outlet pressure, when the outlet pressure is -6500 Pa, the maximum velocity is 67.59 m/s. When the absolute value of the outlet pressure is greater than 6000 Pa, a small amount of steel shot particles is discharged from the recovery bin under the action of the outlet pressure, resulting in the loss of steel shot particles. After the outlet pipe position optimization, the steel shot particle recovery efficiency increased by 10% and the waste particle recovery efficiency increased by 18.9%.

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“…The result demonstrated the heat transfer enhancement of up to 5.4% by using a tri-lobe instead of an oval tube. Yan et al [6] studied the effect of a different pitch to diameter (P:D) and lobe number on the effectiveness of the lobe swirl generator. The result proved that the optimum design of lobe swirl generator was attained at a lobe number of four (n = 4) and (P:D = 8).…”

Section: Introductionmentioning

confidence: 99%

Thermal Performance of Four-Lobe Swirl Generator and its Transition Parts Under a Different Type of Nanofluids

Diabis

Talib²,

Altarazi³

et al. 2022

CFDL

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Due to the importance of promoting the thermal performance of heat exchangers, innovating a new technique is the main goal of many researchers. In swirl flow techniques, keeping the pressure drop at the practical level still requires more and more attention. In the current paper, a numerical study is conducted to explore the impact of a novel lobe swirl generator and its transition parts on forced convective heat transfer and friction factor in a circular pipe subjected to constant heat flux.The swirl mechanism is investigated at the pitch to a diameter of P/D = 8 as the optimum design. The transition part under several parameters of variable beta (β), transition multiplier (n= 0.5) and variable helix (t = 1) have been adopted. The effect of SiO2, Al2O3, and CuO volume concentrations (1 to 5%) in water under various Reynolds numbers (Re) from 15,000 to 35,000 have been carried out. The turbulent swirling flow was modelled using the applicable shear-stress transport (SST) k-ω. The outcome demonstrated an enhancement in heat transfer value ranging from 1.35 to 1.87 with an increased pressure drop value from 1.23 to 1.67. It was also found that using SiO2/water at 5% volume concentration and Re 15000 created the highest thermal performance, with a significant factor of 1.67.

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Numerical evaluation on the decaying swirling flow in a multi-lobed swirl generator

Cited by 8 publications

References 30 publications

Thermo-Hydraulic Performance of Heated Tube with Twisted Delta Winglet Swirler Insert: A Numerical Simulation

Thermo-Hydraulic Performance of Heated Tube with Twisted Delta Winglet Swirler Insert: A Numerical Simulation

Analysis of gas–solid two-phase flow and structure optimization of mobile shot blasting machine recovery device

Thermal Performance of Four-Lobe Swirl Generator and its Transition Parts Under a Different Type of Nanofluids

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