Abstract
The opposed jet configuration presents a canonical geometry suitable for the evaluation of calculation methods seeking to reproduce the impact of strain and re-distribution on turbulent transport in reacting and non-reacting flows. The geometry has the advantage of good optical access and, in principle, an absence of complex boundary conditions. Disadvantages include low frequency flow motion at high nozzle separations and comparatively low turbulence levels causing bulk strain to exceed the turbulent contribution at small nozzle separations. In the current work, fractal generated turbulence has been used to increase the turbulent strain and velocity measurements for isothermal flows are reported with an emphasis on the axis, stagnation plane and the distribution of mean and instantaneous strain rates. Energy spectra were also determined. The instrumentation comprised hot-wire anemometry and particle image velocimetry with the flows to both nozzles seeded with 1 \(\upmu\)m silicon oil droplets providing a relaxation time of ≃ 3 \(\upmu\)s. It is shown that fractal grids increase the turbulent Reynolds number range from 48–125 to 109–220 for bulk velocities from 4 to 8 m/s as compared to conventional perforated plate turbulence generators. Low frequency motion of the order 10 Hz could not be completely eliminated and probability density functions were determined for the location of the stagnation plane. Results show that the fluctuation in the position of the stagnation plane is of the order of the integral length scale, which was determined to be 3.1±0.1 mm at the nozzle exits through the use of hot-wire anemometry. Flow statistics close to the fractal plate located upstream of the nozzle exit were also determined using a transparent glass nozzle.
Article PDF
Similar content being viewed by others
Explore related subjects
Discover the latest articles, news and stories from top researchers in related subjects.Avoid common mistakes on your manuscript.
References
Craft, T.J., Launder, B.E., Suga, K.: Development and application of a cubic eddy-viscosity model of turbulence. Int. Heat J. Fluid Flow 17, 108–115 (1996)
Lindstedt, R.P., Luff, D., Whitelaw, J.H.: Velocity and strain-rate characteristics of opposed isothermal flows. Flow Turbul. Combust. 74, 169–194 (2005)
Kempf, A., Forkel, H., Sadiki, A., Janicka, J., Chen, J.-Y.: Large eddy simulation of counterflow configuration with and without combustion. Proc. Combust. Inst. 28, 35–40 (2000)
Yakhot, V., Orzag, A., Thangam, S., Gatski, T.B., Speziale, C.G.: Development of turbulence models for shear flows by a double expansion technique. Phys. Fluids 4, 1510–1520 (1992)
Haworth, D.C., Pope, S.B.: A generalized langevin model for turbulent flows. Phys. Fluids 29, 387–405 (1986)
Haworth, D.C., Pope, S.B.: A pdf modeling study of self-similar turbulent free shear flows. Phys. Fluids 30, 1026–1044 (1987)
Geyer, D., Kempf, A., Dreizler, A., Janicka, J.: Turbulent opposed-jet flames: a critical benchmark experiment for combustion LES. Combust. Flame 143, 524–548 (2005)
Bray, K.N.C., Champion, M., Libby, P.A.: Premixed flames in stagnating turbulence part II—the mean velocities and pressure and the Damköhler number. Combust. Flame 112, 635–654 (1998)
Rolon, J.C., Veynante, D., Martin, J.P.: Counter jet stagnation flows. Exp. Fluids 11, 313–324 (1991)
Mastorakos, E., Taylor, A.M.K.P., Whitelaw, J.H.: Scalar dissipation rate at the extinction of turbulent counterflow nonpremixed flames. Combust. Flame 91, 55–64 (1992)
Kostiuk, L.W., Bray, K.N.C., Cheng, R.K.: Experimental study of premixed turbulent combustion in opposed streams. Part I—nonreacting flow field. Combust. Flame 92, 377–395 (1993)
Mounaïm-Rousselle, C., Gökalp, I.: Turbulent premixed combustion in counterflow geometry. The influence of a coflow. In: Spring Annual Meeting of the Western States Section of the Combustion Institute (1993)
Sardi, K., Taylor, A.M.K.P., Whitelaw, J.H.: Conditional scalar dissipation statistics in a turbulent counterflow. Fluid J. Mech. 361, 1–24 (1998)
Stan, G., Johnson, D.A.: Experimental and numerical analysis of turbulent opposed impinging jets. AIAA J. 39(10), 1901–1908 (2001)
Geyer, D., Omar, S., Nauert, A., Ludwig, A., Dreizler, A., Janicka, J.: A comprehensive characterisation of a turbulent opposed jet flame by 1D-Raman/Rayleigh, 2D-LIF and 2D-LDV. VDI-Ber. 1750, 435–440 (2003)
Coppola, G., Coriton, B., Gomez, A.: Highly turbulent counterflow flames: a laboratory scale benchmark for practical systems. Combust. Flame 156, 1834–1843 (2009)
Korusoy, E., Whitelaw, J.H.: Extinction and relight in opposed flames. Exp. Fluids 33, 75–89 (2002)
Mastorakos, E.: Turbulent combustion in opposed jet flows. Ph.D. thesis, Imperial College London, UK (1993)
Kostiuk, L.W., Bray, K.N.C., Cheng, R.K.: Experimental study of premixed turbulent combustion in opposed streams. Part II—reacting flow field and extinction. Combust. Flame 92, 396–409 (1993)
Hurst, D., Vassilicos, J.C.: Scaling and decay of fractal-generated turbulence. Phys. Fluids 19(035103), 1–31 (2007)
Seoud, R.E.,Vassilicos, J.C.: Dissipation and decay of fractal generated turbulence. Phys. Fluids 19(105108), 1–11 (2007)
Vassilicos, J.C., Hunt, J.C.R.: Fractal dimensions and spectra of interfaces with application to turbulence. Proc. Roy. Soc. A 435(1895), 505–534 (1991)
Lindstedt, R.P., Luff, D.S.: Velocity fields of lean premixed turbulent opposed jet flames. Proc. Combust. Inst. 31, 1459–1466 (2007)
Kostiuk, L.W., Shepherd, I.G., Bray, K.N.C.: Experimental study of premixed turbulent combustion in opposed streams. Part III—spatial structure of flames. Combust. Flame 118, 129–139 (1999)
Mastorakos, E., Taylor, A.M.K.P., Whitelaw, J.H.: Extinction of turbulent counterflow flames with reactants diluted by hot products. Combust. Flame 102, 101–114 (1995)
Sardi, K., Whitelaw, J.H.: Extinction timescales of periodically strained, lean counterflow flames. Exp. Fluids 27, 199–209 (1999)
Mastorakos, E., Taylor, A.M.K.P., Whitelaw, J.H.: Extinction and temperature characteristics of turbulent counterflow diffusion flames with partial premixing. Combust. Flame 91, 40–54 (1992)
Sardi, K., Taylor, A.M.K.P., Whitelaw, J.H.: Extinction of turbulent counterflow flames under periodic strain. Combust. Flame 120, 265–284 (2000)
Luff, D.S.: Experiments and calculations of opposed and ducted flows. Ph.D. thesis, Imperial College London, UK (2005)
Kostiuk, L.W.: Premixed turbulent combustion in counterflowing streams. Ph.D. thesis, Churchill College, University of Cambridge (1991)
Han, D., Mungal, M.G.: Simultaneous velocity and CH distributions. Part I: Jet flames in a co–flow. Combust. Flame 132, 565–590 (2003)
Denshchikov, V.A., Kontratev, V.N., Romashev, A.N.: Interaction between two opposed jets. Fluid Dyn. 13(6), 313–324 (1978)
Denshchikov, V.A., Kontratev, V.N., Romashev, A.N., Chubarov, V.M.: Auto-oscillation of planar colliding jets. Fluid Dyn. 18(3), 460–462 (1978)
Mounaïm-Rousselle, C., Gökalp, I.: Strain effects on the structure of counterflowing turbulent premixed flames. Proc. Combust. Inst. 25, 1199–1205 (1994)
Korusoy, E., Whitelaw, J.H.: Opposed jets with small separations and their implications for the extinction of opposed flames. Exp. Fluids 31, 111–117 (2001)
Pope, S.B.: Turbulent Flows. Cambridge University Press, Cambridge, UK (2000)
von Kármán, T.: Progress in the statistical theory of turbulence. Proc. Natl. Acad. Sci. USA 34, 530–539 (1948)
Kraichnan, R.H.: The structure of isotropic turbulence at very high Reynolds numbers. J. Fluid Mech. 5, 497–543 (1959)
Pao, Y.-H.: Structure of turbulent velocity and scalar fields at large wavenumbers. Phys. Fluids 8, 1063–1075 (1965)
Comte-Bellot, G., Corrsin, S.: Simple Eulerian time correlation of full- and narrow-band velocity signals in grid-generated, isotropic turbulence. J. Fluid Mech. 48(02), 273–337 (1971)
Author information
Authors and Affiliations
Corresponding author
Additional information
Submitted for the Special Issue dedicated to S.B. Pope.
Rights and permissions
About this article
Cite this article
Geipel, P., Goh, K.H.H. & Lindstedt, R.P. Fractal-Generated Turbulence in Opposed Jet Flows. Flow Turbulence Combust 85, 397–419 (2010). https://doi.org/10.1007/s10494-010-9288-x
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10494-010-9288-x