Turbulent jets

Values of interfacial tension of nucleus from turbulent jet measurements, by various equations [44]. 

Fig. 17. Comparison of the predictions of k-Q model with experimental data for a turbulent jet inside a 5° conical duct, (a) Flow geometry and inlet conditions, where geometry =1.6 cm, = 16 cm, L = 64 cm, 0 = 5°-, flow conditions, p = 0.998 g/mc, p = 0.01 g/cm-s, Uj = 40 cm/s,...

For a known flow rate the no22le diameter is set by the largest si2e that satisfies the turbulent jet requirement for both heavy and light jets, ie,... 

Abramovich, G. N. 1960. Theory of Turbulent Jets. Fizrnatgiz, Moscow. 

Heskestad, G. 1966. Hot-wire measurements in a radial turbulent jet. Transactions A.SiVlE Journal of Applied Mechanics, no. 33, pp. 417-H24. 

Zhivov, A. M. 1982. Investigation of the interaction of axially symmetric turbulent jets supplied under straight angles to each other. In Turbulent Jet Flows Theses of Reports of the Fourth All Union Scientific Conference on Theoretical and Applied Aspects of Turbulent Flows, part II. Estonian Academy of Sciences, Tallinn,... 

Vulis, L. A. 1960. Regarding free turbulent jets computation applying the heat conductivity method. In Proceedings of Acad. Set. Kaz. SSR, Ser. Energy, vol. 2, no. 18. 

Mizuchina, T. 1982. An experimental study of vertical turbulent jet with negative buoyancy. Vi drrne- u. Stoffuhertragung, vol. 16, no. 1. 

T Hndcnko, B. G. 1966. About the calculation of turbulent jet mixing based on the principle of superimposing. In Studies of Heat and Mass Exchange in Production Processe, in qwp ment. Science and Technology, Minsk. 

Beltaos, S. 1976. Oblique impingement of circular turbulent jets. Journal cjf Hydraulic Research, vol. 14, no, 1, pp. 17-36. 

Ginevskii, A. S. 1969. Theory of turbulent jets and wakes. Mashinostroyeniye,. Moscow. 

Karimipanah, T. 1996. Turbulent jets in confined spaces. Ph.D. thesis. Royal Institute of Technology, Center for Built Environment, Gavle, Sweden. 

Trapani, R. D. 1967. An experimental study of bounded and confined turbulent jets. In Advances in Fluidics The 1967 Fluidics Symposium, pp. 1-13. ASME, New York. 

Wygnanski, 1. 1964. The flow induced by two-dimensional and axisymmetric turbulent jets issuing normally from an infinite plane surface. Aeronautical Quarterly, November, pp. 373-580. 

The influence of the geometrical parameters is not well described in the literature and the design of an air curtain is based on theoretical models of a plane turbulent jet. 

The above discussion holds for dispersion by atmospheric turbulence. In addition, a momentum release of fuel sometimes generates its own turbulence, e.g., when a fuel is released at high pressure in the form of a high-intensity turbulent jet. Fuel mixes rapidly with air within the jet. Large-scale eddy structures near the edges of the jet entrain surrounding air. Compositional homogeneity, in such cases, can be expected only downstream toward the jet s centerline. 

Source-term turbulence, as would be caused by vessel rupture or after a turbulent jet release, enhances combustion in vapor clouds. 

A detailed study performed by McKay et al. (1989) revealed some of the conditions necessary for a turbulent jet to initiate a detonation directly. These experiments are covered in more detail in Section 4.1.5. 

On the other hand, turbulence may also be generated by external sources. For example, fuels are often stored in vessels under pressure. In the event of a total vessel failure, the liquid will flash to vapor, expanding rapidly and producing fast, turbulent mixing. Should a small leak occur, fuel will be released as a high-velocity, turbulent jet in which the fuel is rapidly mixed with air. If such an intensely turbulent fuel-air mixture is ignited, explosive combustion and blast can result. 

Stock, M., W. Geiger, and H. Giesbrecht. 1989. Scaling of vapor cloud explosions after turbulent jet release. 12th Int. Symp. on the Dynamics of Explosions and Reactive Systems. Ann Arbor, MI. 

W. M. Pitts, Assessment of theories for the behavior and blowout of lifted turbulent jet diffusion flames, Proc. Combust. Inst. 22 809-816, 1988. 

Figure 7.2.5 provides a visualization of a localized extinction event in a turbulent jet flame, using a temporal sequence of OH planar LIF measurements. The OH-LIF measurements, combined with particle image velocimetry (PIV) reveal that a distinct vortex within the turbulent flow distorts and consequently breaks the OH front. These localized extinction events occur intermittently as the strength of the coupling between the turbulent flow and the flame chemistry fluctuates. The characteristics of the turbulent flame can be significantly altered as the frequency of these events increases. 

Clemens, N.T., Paul, P.H., and Mungal, M.G., The structure of OH fields in high Reynolds number turbulent jet diffusion flames. Combust. Sci, Technol., 129,165,1997. 

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