DNS study of dependence of bulk consumption velocity in a constantdensity reacting flow on turbulence and mixture characteristics
(2017) In Physics of Fluids 29(6). Abstract
3D Direct Numerical Simulation (DNS) study of propagation of a singlereaction wave in forced, statistically stationary, homogeneous, isotropic, and constantdensity turbulence was performed in order to evaluate both developing U^{t} _{T} and fully developed U^{s} _{T} bulk turbulent consumption velocities by independently varying a ratio of 0.5 ≤ u'=S_{L} ≤ 90 of the r.m.s. turbulent velocity to the laminar wave speed and a ratio of 0.39 ≤ L11=δF ≤ 12.5 of the longitudinal integral length scale of the turbulence to the laminar wave thickness. Accordingly, the Damköhler Da = (L_{11}S_{L})=(u'δ_{F}) and Karlovitz Ka = δ_{F}=(S_{L}τ_{η}) numbers were... (More)
3D Direct Numerical Simulation (DNS) study of propagation of a singlereaction wave in forced, statistically stationary, homogeneous, isotropic, and constantdensity turbulence was performed in order to evaluate both developing U^{t} _{T} and fully developed U^{s} _{T} bulk turbulent consumption velocities by independently varying a ratio of 0.5 ≤ u'=S_{L} ≤ 90 of the r.m.s. turbulent velocity to the laminar wave speed and a ratio of 0.39 ≤ L11=δF ≤ 12.5 of the longitudinal integral length scale of the turbulence to the laminar wave thickness. Accordingly, the Damköhler Da = (L_{11}S_{L})=(u'δ_{F}) and Karlovitz Ka = δ_{F}=(S_{L}τ_{η}) numbers were varied from 0.01 to 24.7 and from 0.36 to 587, respectively. Here, τ is the Kolmogorov time scale. The obtained DNS data show that, at sufficiently low Da, the fully developed ratio of U^{s} _{T}/u' is mainly controlled by Da and scales as p Da. However, such a scaling should not be extrapolated to high Da. The higher Da (or the lower Ka), the less pronounced dependence of U^{s} _{T}/u' on a ratio of L_{11}/δ_{F}. Moreover, scaling laws U_{T} α u'αS^{1α} _{L}(L_{11}=δ_{F})^{β} are substantially different for developing U^{t} _{T} and fully developed U^{s} _{T} , i.e., the scaling exponents α and, especially, β depend on the wavedevelopment time. Furthermore, α and, especially, depend on a method used to evaluate the developing U^{t} _{T} . Such effects can contribute to significant scatter of expressions for U_{T} or S_{T} as a function of (u', S_{L}, L_{11}, δ_{F}), obtained by parameterizing various experimental databases.
(Less)
 author
 Yu, Rixin ^{LU} and Lipatnikov, Andrei N.
 organization
 publishing date
 20170601
 type
 Contribution to journal
 publication status
 published
 subject
 in
 Physics of Fluids
 volume
 29
 issue
 6
 publisher
 American Institute of Physics
 external identifiers

 scopus:85021856287
 wos:000404636900045
 ISSN
 10706631
 DOI
 10.1063/1.4990836
 language
 English
 LU publication?
 yes
 id
 9cd86f62f69941fd985b2fabb177c76a
 date added to LUP
 20170724 12:30:39
 date last changed
 20180107 12:12:47
@article{9cd86f62f69941fd985b2fabb177c76a, abstract = {<p>3D Direct Numerical Simulation (DNS) study of propagation of a singlereaction wave in forced, statistically stationary, homogeneous, isotropic, and constantdensity turbulence was performed in order to evaluate both developing U<sup>t</sup> <sub>T</sub> and fully developed U<sup>s</sup> <sub>T</sub> bulk turbulent consumption velocities by independently varying a ratio of 0.5 ≤ u'=S<sub>L</sub> ≤ 90 of the r.m.s. turbulent velocity to the laminar wave speed and a ratio of 0.39 ≤ L11=δF ≤ 12.5 of the longitudinal integral length scale of the turbulence to the laminar wave thickness. Accordingly, the Damköhler Da = (L<sub>11</sub>S<sub>L</sub>)=(u'δ<sub>F</sub>) and Karlovitz Ka = δ<sub>F</sub>=(S<sub>L</sub>τ<sub>η</sub>) numbers were varied from 0.01 to 24.7 and from 0.36 to 587, respectively. Here, τ is the Kolmogorov time scale. The obtained DNS data show that, at sufficiently low Da, the fully developed ratio of U<sup>s</sup> <sub>T</sub>/u' is mainly controlled by Da and scales as p Da. However, such a scaling should not be extrapolated to high Da. The higher Da (or the lower Ka), the less pronounced dependence of U<sup>s</sup> <sub>T</sub>/u' on a ratio of L<sub>11</sub>/δ<sub>F</sub>. Moreover, scaling laws U<sub>T</sub> α u'αS<sup>1α</sup> <sub>L</sub>(L<sub>11</sub>=δ<sub>F</sub>)<sup>β</sup> are substantially different for developing U<sup>t</sup> <sub>T</sub> and fully developed U<sup>s</sup> <sub>T</sub> , i.e., the scaling exponents α and, especially, β depend on the wavedevelopment time. Furthermore, α and, especially, depend on a method used to evaluate the developing U<sup>t</sup> <sub>T</sub> . Such effects can contribute to significant scatter of expressions for U<sub>T</sub> or S<sub>T</sub> as a function of (u', S<sub>L</sub>, L<sub>11</sub>, δ<sub>F</sub>), obtained by parameterizing various experimental databases.</p>}, articleno = {065116}, author = {Yu, Rixin and Lipatnikov, Andrei N.}, issn = {10706631}, language = {eng}, month = {06}, number = {6}, publisher = {American Institute of Physics}, series = {Physics of Fluids}, title = {DNS study of dependence of bulk consumption velocity in a constantdensity reacting flow on turbulence and mixture characteristics}, url = {http://dx.doi.org/10.1063/1.4990836}, volume = {29}, year = {2017}, }