Flow structure in critical flow Venturi nozzle and its effect on the flow rate

Lavante, E. von; Kaya, Hüseyin; Winzösch, F.; Brinkhorst, S.; Mickan, Bodo

doi:10.1016/j.flowmeasinst.2014.12.003

Cited by 8 publications

(6 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For the transition boundary layer, the Cd had a reduced 'jump down', while in the turbulent boundary layer, the Cd also showed a tiny increasing tendency. Besides, it also obtained conclusion that the transition position of 1.919 mm sonic nozzle is at the Retr of 3.9×10 5 rather than 1×10 6 ~ 2×10 6 . By fitting the experimental data of each nozzle with the reference of 'S-CURVE' by Ishibahsi [5] , the curve of the Cd covered the whole boundary layer of laminar, transition and turbulent flows, where defines the Reynolds number from laminar to transition regime as 'Begin Reynolds number, Retr,beg', and the Reynolds number turning into full turbulence regime defined as 'End Reynolds number, Retr,end', namely the beginning and ending positions of the viscous flow transition.…”

Section: Results Of the CDmentioning

confidence: 80%

“…In 1964, Stratford [1] found that the boundary layer transition from laminar to turbulent taking place at the Reynolds number of between 1×10 6 and 2×10 6 through experimental study. In 1992, Demetriades [2] measured the Reynolds number (Retr) of the boundary layer transition under different roughness by using the hot film anemometer, and found that the Retr decreased with the increase of surface roughness.…”

Section: Introductionmentioning

confidence: 99%

“…In order to avoid the transition of boundary layer, ultra-precision sonic nozzle was selected to ensure that the fluid flow is always in the region of laminar boundary layer. In the same year, Lavante [6] used the intermittent factor γ for the first time to predict the influence of free turbulence intensity Tu on the boundary layer transition, but he did not consider the additional effect for wall roughness. In 2015 and 2016, Wang and Ding 错误 !…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effect of Different Conditions on the Boundary Layer Transition of Sonic Nozzle

Cao¹,

Sun²,

Zhang³

et al. 2023

Proceedings of the 19th International Flow Measurement Conference 2022 on Flow Measurement - FLOMEKO 2022

View full text Add to dashboard Cite

The boundary layer transition of sonic nozzle is affected by many factors, including Reynolds number, macro structure (throat diameter), meso-micro surface structure (wall roughness, waviness), turbulence intensity, wall heat transfer and so on. Therefore, in order to analyse the influences of macrostructure, meso-micro surface structure and turbulence intensity on boundary layer transition, the Cd and geometric dimension (throat diameter, d, average roughness, Ra, maximum roughness, Rz, and waviness, wa) of sonic nozzles with throat diameter of 1.919 mm, 3.808mm, and 7.453 mm were experimental investigated and measured. Furthermore, a series of CFD simulations through the transition SST model for axisymmetric nozzles were established to research the variation law of boundary layer transition and Cd of the sonic nozzle when Reynolds numbers ranges from 4.6×10 4 to 4.7×10 7 and different turbulence intensity (Tu) and meso-micro surface structure (Ra, Rz and wa). The validity of the simulation model was confirmed by the experimental data of National Institute of Metrology of China (NIM). Finally, the relationships between the boundary layer transition and Tu, Ra, Rz and wa were obtained.

show abstract

Section: Results Of the CDmentioning

confidence: 80%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effect of Different Conditions on the Boundary Layer Transition of Sonic Nozzle

Cao¹,

Sun²,

Zhang³

et al. 2023

Proceedings of the 19th International Flow Measurement Conference 2022 on Flow Measurement - FLOMEKO 2022

View full text Add to dashboard Cite

show abstract

“…Mousavi and Roohi [7] investigated the shock train in a three-dimensional convergent-divergent nozzle for compressible and turbulent fluid flow using Reynolds stress turbulence model (RSM) which is validated with the experimental data. Lavante et al [8] investigated the flow behavior, shock structure and choking phenomenon in CFVN for exit pressure ratio vary in between 0.2 and 0.8 and at different Reynolds number (Laminar or turbulent) using self-developed Navier-Stokes solver ACHIEVE program and commercial code CD-adapco Star CCM+. Pengfei et al [9] developed half-flexible single jack nozzle for supersonic free jet used in wind tunnel to achieve better aerodynamic performance, mechanical property, and continuous Mach number regulation.…”

Section: Introduction mentioning

confidence: 99%

Design and Numerical Investigation to Predict the Flow Pattern of Non-axisymmetric Convergent Nozzle: A Component of Turboexpander

Kumar¹,

Panda²,

Biswal³

et al. 2019

JTTE

View full text Add to dashboard Cite

Current work proposes a novel design methodology using curve-fitting approach for a non-axisymmetric airfoil convergent nozzle used in small-sized cryogenic turboexpander. The curves used for designing the nozzle are based on a combination of fifth and third order curve at upper and lower surface respectively. Four different turbulence model such as k-ε, SST, BSL and SSG Reynolds stress turbulence model is used to visualize and compare the fluid flow characteristics and thermal behaviors at various cross-sections. It is interesting to observe that the Mach number obtained at the outlet of the nozzle is highest and temperature drop is maximum for SSG model under similar boundary conditions. It is also observed that the designed nozzle with curve fitting approach is appropriate for impulse type turbine with a small amount of reaction. The key feature of this implementation is to obtain subsonic velocity at the nozzle exit and reduce the irreversible losses through the nozzle, which can affect the performance of a turboexpander.

show abstract

“…The typical theoretical formulas include the normal distribution, logarithmic normal distribution, maximum entropy distribution [1] etc. [2][3][4][5][6][7][8][9][10][11] The representative studies on spray atomization features of nozzles are as follows. Targeted at fuel atomizer nozzles, Lefebvre [12] summed up the nozzle flow, atomization, external flow and droplet distribution of many kinds of nozzles, including but not limited to flat orifice nozzles, vortex nozzles, rotating nozzles and air-assisted nozzles, and detailed the applicable ranges of various empirical formulas on droplet diameters.…”

Section: Introductionmentioning

confidence: 99%

Stability of secondary atomization locations of atomizer nozzles for humidification chambers

Huang¹,

Zhang²,

Xu³

2017

IJHT

View full text Add to dashboard Cite

This paper aims to reveal the atomization features of nozzles for humidification chambers. Targeted at three commonly used nozzles (TF6, TF8 and AM4), the author investigated into the effect of nozzle backpressure on droplet size, and examined the diameters and distribution spans of the droplets at different distances to the nozzle. The results show that the droplet diameters decreased with the increase in spray pressure. However, there was a critical value of the pressure. The location of secondary atomization was determined by analysing the atomization features at different locations below the nozzle. It is concluded that the location is 7cm below the nozzle for TF6 nozzle, 12cm below the nozzle for TF8 nozzle, and 10cm below the nozzle for AM4 nozzle. Moreover, the least square method was used to fit an empirical correlation for the droplets atomized by the nozzle in the secondary atomization area. The empirical correlation was then converted to a functional relation of the Weber number and Reynolds number. The research findings make it possible to predict the particle diameters from the nozzle exit.

show abstract

Flow structure in critical flow Venturi nozzle and its effect on the flow rate

Cited by 8 publications

References 6 publications

Effect of Different Conditions on the Boundary Layer Transition of Sonic Nozzle

Effect of Different Conditions on the Boundary Layer Transition of Sonic Nozzle

Design and Numerical Investigation to Predict the Flow Pattern of Non-axisymmetric Convergent Nozzle: A Component of Turboexpander

Stability of secondary atomization locations of atomizer nozzles for humidification chambers

Contact Info

Product

Resources

About