Numerical Simulation of Turbulent Jets

Abstract

In this study, plane and circular turbulent non-buoyant jets are simulated numerically using a threedimensional computational model. The aim of the study is to evaluate the accuracy of turbulent closure schemes employed in three-dimensional models. In particular, standard k−ε and renormalized group k−ε schemes with standard coefficients are evaluated. The modeled jets are deeply submerged, that is the impact of free surface and solid boundaries on jets are eliminated. The accuracy of the turbulent schemes is assessed by analyzing the decay of centerline velocity, jet growth rates, similarity of longitudinal and vertical velocity profiles, and turbulent kinetic energy profiles. The results from the two turbulent closure schemes are compared with accepted experimental and theoretical studies to determine their accuracy. It is found that the k−ε scheme with standard coefficient performs equally well and in some cases better than the renormalized group k−ε scheme. Finally, the model is applied to analyze flow pattern in the Sampit River, South Caroline, USA, resulting from stormwater discharge in a recreational area. Various inlet designs are investigated and box inlet is found to provide a practical means of localizing high surface currents.

Simulation of Vertical Plane Turbulent Jet in Shallow Water

“…In the ZEF zone (Figure 9), the lateral velocity profiles predicted by the k-ε scheme agree well with (10), while in the case of the RNG scheme, velocity profiles are progressively underpredicted with increasing longitudinal distance. The zone of surface impingement is where the flow turning and acceleration take place.…”

“…The two most common turbulence closure schemes are the k-ε and the renormalized group k-ε (RNG). For free plane turbulent jets the two schemes provide similar results in the zone of established flow with RNG providing better results for the turbulent kinetic energy along the center of the jet [10]. The aim of this study is to assess the applicability of these two turbulence closure schemes in predicting the mean and turbulent flow characteristics of a jet issuing vertically upward in shallow water.…”

Comparison of flow and dispersion properties of free and wall turbulent jets for source dynamics characterisation

“…The amount of data available is substantial as many researchers have compared their results to Forthmann's for the characterisation of self-similarity profiles. The simulation results are also compared with analytical results of Tollmien (Abramovich, 1963) and Goertler (Abramovich, 1963), Zijnen's Gaussian profile (Van der Hegge Zijnen, 1958), a sech 2 profile (Thorne, 2004), and recent analytical expressions of Morchain et al (2000) and Aziz et al (2008).…”

Dynamics of Sonic Hydrogen Jet Injection and Mixing Inside Scramjet Combustor

“…They also demonstrated computational efficiency obtained using the methodology. Further studies of similar interest have been presented by Aziz et al (2008), Wasewar and Sarathi (2008) and Liu and Wang (2011). The work presented in this article utilizes the same ILES approach using high resolution methods to study the flow of a transverse sonic hydrogen jet injected into the free-stream turbulent supersonic (Mach number 2.5) flow of air.…”