The Theory of Turbulent Jets

Abramovich, G. N.

doi:10.7551/mitpress/6781.001.0001

Cited by 198 publications

(294 citation statements)

References 0 publications

Supporting

Mentioning

255

Contrasting

Unclassified

Order By: Relevance

“…The need for reliable wake modelling has been recognized for many years, and various models have been developed to simulate the W/T wakes. Many of them are simple kinematic models based on self‐similar velocity deficit profiles obtained from experimental and theoretical work on mixing jets 1–3. A more advanced approach is that of the field (or implicit) models that calculate the flow quantities at every point of the flow field giving a better insight into the physical mechanisms that govern the wake development.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of the effects of turbulence model enhancements on wind turbine wake predictions

et al. 2010

View full text Add to dashboard Cite

The modelling of wind turbine wakes is investigated in this paper using a Navier-Stokes solver employing the k-ω turbulence model appropriately modifi ed for atmospheric fl ows. It is common knowledge that even single-wind turbine wake predictions with computational fl uid dynamic methods underestimate the near wake defi cit, directly contributing to the overestimation of the power of the downstream turbines. For a single-wind turbine, alternative modelling enhancements under neutral and stable atmospheric conditions are tested in this paper to account for and eventually correct the turbulence overestimation that is responsible for the faster fl ow recovery that appears in the numerical predictions. Their effect on the power predictions is evaluated with comparison with existing wake measurements. A second issue addressed in this paper concerns multi-wake predictions in wind farms, where the estimation of the reference wind speed that is required for the thrust calculation of a turbine located in the wake(s) of other turbines is not obvious. This is overcome by utilizing an induction factor-based concept: According to it, the defi nition of the induction factor and its relationship with the thrust coeffi cient are employed to provide an average wind speed value across the rotor disk for the estimation of the axial force. Application is made on the case of fi ve wind turbines in a row.Modelling of wind turbine wakes J. M. Prospathopoulos et al.

show abstract

Section: Introductionmentioning

confidence: 99%

Evaluation of the effects of turbulence model enhancements on wind turbine wake predictions

et al. 2010

View full text Add to dashboard Cite

show abstract

“…When the standoff distance and nozzle diameter are settled, the velocity within jet range radially decreases away from the center line, which can be described as a bell‐shaped profile. Further, the velocity distribution on each of jet cross section can be expressed by characteristic variables of velocity and scaled into the same mathematical model as shown in Equation , namely the self‐similarity of jet velocity distribution . The results of ground test (see Figure ) showed the core impacting length of waterjet has a linear increase with jet velocity.…”

Section: Resultsmentioning

confidence: 99%

Optimal submerged waterjet for gas recovery based on Arbitrary Lagrange‐Euler

Wang

Hai

et al. 2019

Energy Science & Engineering

View full text Add to dashboard Cite

This paper proposes a coupled model of waterjet cutting coal containing gas with the Arbitrary Lagrange‐Euler algorithm assistance. The dynamic evolution of coal damage and the cutting performance under different jet conditions, including jet pattern (submerged/nonsubmerged state), jet velocity, nozzle diameter, and the initial standoff distance, are investigated by tracing the number of failure elements and the stress distribution. Afterward, the gas flow model is built to study interactions of the discharged coal amount and the effective drainage radius at different periods with COMSOL software. The numerical results show the coal cutting performance of nonsubmerged jets is much better than that of submerged jets. Under submerged conditions, the penetration length increases with jet velocity and nozzle diameter, but decreases with the initial standoff distance. Moreover, the effective drainage radius of nonsubmerged waterjet is substantially greater than that of submerged jet. The increasing trend of the effective drainage radius slows down after 3 months with gas flow attenuation. Under the special submerged circumstances, the difference of coal cutting performance caused by the two jet patterns should be fully considered in order to reasonably arrange the spacing of boreholes.

show abstract

“…( ) is density of water and air mixture at actual distance; S is cross section of nozzle; x is distance; r is radius of nozzle. Figure 9 shows schematic velocity profile calculated by (12) applied on surfaces of profile in the FEM analysis [8,9] All of these ingredients were implemented in our in-house massively parallel code ESPRESO, which is a massively parallel framework based on the finite element method for engineering application. The free license for the developed package allows automatized simulation chains such as automatized systems for optimization to be created above the "solver as a service" platform.…”

Section: Fem Simulationmentioning

confidence: 99%

Numerical Simulation of Heat Treatment Process of Aluminium Profiles

Gebauer

Brzobohatý

Blejchař

et al. 2019

Strojnícky Časopis - Journal of Mechanical Engineering

View full text Add to dashboard Cite

The paper deals with the simulation of cooling processes of the aluminium profiles inside the water quench. Cooling of profile surfaces is performed by water spray, which is created by mixing a water and an air in a nozzles. Formulas were found in literature, modified and applied to a given problem that significantly simplified a solution. The task of numerical simulations was to determine temperature and velocity profile on aluminium profile surfaces for establishing of the heat transfer coefficient which was used as the convective boundary condition necessary to solve the heat transfer in the aluminium profile by finite element method. The difference between FEM and CFD results is up to 10%.

show abstract

The Theory of Turbulent Jets

Cited by 198 publications

References 0 publications

Evaluation of the effects of turbulence model enhancements on wind turbine wake predictions

Evaluation of the effects of turbulence model enhancements on wind turbine wake predictions

Optimal submerged waterjet for gas recovery based on Arbitrary Lagrange‐Euler

Numerical Simulation of Heat Treatment Process of Aluminium Profiles

Contact Info

Product

Resources

About