Research Journal of Mathematics and Statistics 4(2): 30-38, 2012 ISSN: 2040-7505 © Maxwell Scientific Organization, 2012 Submitted: April 03, 2012 Accepted: April 30, 2012 Published: June 30, 2012 First-order Reactant in Homogeneous Dusty Fluid Turbulence Prior to the Ultimate Phase of Decay for Four-Point Correlation in a Rotating System M.A. Bkar PK, M.A.K. Azad and M.S.A. Sarker Department of Applied Mathematics, Rajshahi University, Rajshahi 6205, Bangladesh Abstract: The aim of this study is to find the decay of energy in homogeneous dusty fluid turbulence at times preceding to the ultimate phase for the concentration fluctuation of a dilute contaminant due to a first order chamical reaction in a rotating system for the case of four-point correlation. Following Deissler’s approach, two-, three-and four-point correlation equations have obtained and these equations are converted to spectral form by their Fourier-transform, the terms containing quintuple correlations are neglected in comparison to the third and fourth order correlation terms. Finally, integrating the energy spectrum over all wave numbers, the energy decay law of homogeneous dusty fluid turbulence for the concentration fluctuations ahead of the ultimate phase in a rotating system is obtained. Keywords: Deissler’s method, dusty fluid, first-order reactant, rotating system, turbulent flow Astrophysics and Stellar dynamics. It is also significant in the Earth sciences, especially Meteorology, Physical geology and Oceanography. Deissler (1958, 1960) developed a theory ‘on the decay of homogeneous turbulence before the final period.’ Using Deissler theory, Kumar and Patel (1974) studied the first-order reactant in homogeneous turbulence before the final period of decay for the case of multi-point and single-time correlation. Kumar and Patel (1975) extended their problem for the case of multi-point and multi-time concentration correlation. Loeffler and Deissler (1961) studied the decay of temperature fluctuations in homogeneous turbulence before the final period. Batchelor (1953) studied the theory of homogeneous turbulence. Chandrasekhar (1951) obtained the invariant theory of isotropic turbulence in magneto-hydrodynamics. Sarker and Kishore (1991) studied the decay of MHD turbulence before the final period. Sarker and Islam (2001) obtained the decay of dusty fluid MHD turbulence before the final period in a rotating system. Sultan (2008) studied the energy decay law of dusty fluid turbulent flow in a rotating system. Aziz et al. (2009) studied the first order reactant in MHD turbulence before the final period of decay for the case of multi-point and multi-time in a rotating system. Aziz et al. (2010) also extended their previous problem in presence of dust particle. It is noted that in all above cases, the researcher had considered three-point correlations and through their study they obtained the energy decay law ahead of the ultimate phase, by analyzing the above theories we have studied the first-order reactant in homogeneous dusty INTRODUCTION In recent year, the motion of dusty viscous fluids in a rotating system has developed rapidly. The motion of dusty fluid occurs in the movement of dust-laden air, in problems of fluidization, in the use of dust in a gas cooling system and in the sedimentation problem of tidal rivers. The behavior of dust particles in a turbulent flow depends on the concentrations of the particles and the size of the particles with respect to the scale of turbulent fluid. In geophysical flows, the system is usually rotation with a constant velocity, such large Scale flows are generally turbulent. Gustave Coriolis, French engineer and mathematician, who showed that a force could be used to allow the use of the ordinary laws of motion in a rotating reference frame. The Coriolis Effect is caused by the rotation of the Earth and the inertia of the mass experiencing the effect. The most commonly encountered rotating reference frame in the Earth. Because the Earth completes only one rotation per day, this force causes moving objects on the surface of the Earth to appear to change direction to the right in the northern hemisphere and to the left in the southern. This effect is responsible for the rotation of large cyclones. The acceleration entering the Coriolis force arises from two sources of change in velocity that result from rotation: the first is the change of the velocity of an object in time; the second is the change of velocity in space. Different positions in a rotating frame of reference have different velocities. The nature and size of the Coriolis effects depend upon where we are. The Coriolis Effect has great significance in Corresponding Author: M.A. Bkar PK, Department of Applied Mathematics, Rajshahi University, Rajshahi 6205, Bangladesh 30 Res. J. Math. Stat., 4(2): 30-38, 2012 XX ' XX ' 2 XX ' uk D R XX ' t xk xk xk fluid turbulence prior to the ultimate phase of decay for four-point correlation in a rotating system. Through this study we would like to find the decay law of first order reactant in homogeneous dusty fluid turbulence in a rotating system. Later we shall try to show in this study when the reaction rate R = 0 causes the concentration fluctuation of decay more rapidly than for R…0, non pure mixing dusty fluid turbulence. where, X!j is the fluctuating concentration at the point p! x and the point p! is at point a distance r from the point p. The symbol + , is the ensemble average. Putting the Fourier transforms: Basic equation: The differential equation governing the concentration of a dilute contaminant undergoing a firstorder chemical reaction in homogeneous dusty fluid turbulence in a rotating system could be written as: (5) (6) uk XX ' r k K , t exp i K , r dK u'k XX ' r k K , t exp i K . r dK ui ui 2 ui uk D Rui 2 mki m ui f ui vi (1) t xk xk xk (7) into Eq. (4), one obtains: where, ui x is a random function of position and time at a point p, uk x , t is the turbulent velocity, R is the constant reaction rate, D is the diffusivity, t is the time, gmki is the alternating tensor, Sm is the angular velocity components, kN , dimension of frequency; N, constant number f Dk 2 2 R ik k k K , t K K , t t (8) Three-point correlation and spectral equations: The same procedure can be used to find the three-point correlation, i.e., by taking the Navier-Stokes equations for a first-order chemical reaction in homogeneous dusty fluid turbulence in a rotating system at p is: density of dust particle, ms 4 Rs3s is the mass of single 3 spherical dust particle of radius Rs, Ds is the constant density of the material in dust particle, ui is the turbulent velocity component, vi is the dust particle velocity component, xk is the space coordinate and repeated subscript in a term indicates a summation of terms, with the subscripts successively taking on the values 1, 2 and 3. ui ui 2 ui uk D Rui 2 mki m ui f ui vi t xk xk xk and the fluctuation equations at p! & p" one can find the three-point correlation equation as: Two-point correlation and spectral equations: Under the restrictions that the turbulence and the concentration fields are homogeneous, the local mass transfers have no effect on the velocity field and the reaction rate and the diffusivity are constant. The differential equation of a dilute contaminant undergoing a first-order chemical reaction in homogeneous system could be written as: ui X X uk uk X X ui uk X X ui uk X X t xk x k x k 2 ui X X 1 pX X v xi xk xk 2 2 u X X 2 R ui X X 2 mki m ui X X D x k x k x k x k i (2) f ui X X vi X X Subtracting the mean of (2) from Eq. (2), we obtain: X X X uk D RX t xk xk xk XX ' r K , t exp i K . r dK MATERIALS AND METHODS 2 uk D R t xk xk xk (4) (9) Using the transformations: 2 , , xk rk rk x k x k x k rk (3) where, X x , t is the fluctuation of concentration about the mean at a point p x and time t. The two-point correlation for the fluctuating concentration can be written, as: In order to convert Eq. (9) to spectral form, using sixdimensional Fourier transforms (Kumar and Patel, 1974) and: 31 Res. J. Math. Stat., 4(2): 30-38, 2012 vi X X i K , K , t .exp i K . r K . r dKdK 2 R ui uj X X 2mki m ui uj X X 2 2 u u X X D x k x k x k x k i j with the fact that: ui uk X X ui uk X X f one can write Eq. (9) in the form: 1 i k j k j where, K , K , t = L i K , K , t and 1-L = Q , with L and Q i arbitrary constants. If the momentum Eq. (3) at p is multiplied by X!X" and divergence of the time averages is taken, the resulting equation will be: 1 (14) In order to convert Eq. (14) to spectral form, using nine-dimensional Fourier transforms (Kumar and Patel, 1974) and: (11) vi uj X X r, r , r ij K , K , K , t dK exp i K . r K . r dKdK In Fourier space it can be written as: k k k k ik , xk rk rk rk , , x k x k x k r k x k rk (10) 2 2 ui uk X X 1 pX X xi x k xi xi vi uj X X i j Using the transformations: 2 v K K D K K 2 R 2 mki m Qf j t i k k k k jk i k k k k jk u u X X ki ki and with the fact that: (12) ukui uj X X r, r , r ukui uj X X r, r , r Substituting this into Eq. (10), we obtain Equation (14) can be written as: j 2 v K K D K K 2 R 2 mki m Qf j t (13) i k k k k jk gij 2 v K K K vK 2 t D K K t ui uk u j X X xk ui u j uk X X x k k K K K , K , K j K , K , K 1 i k k k k hijk K , K , K ki ki ki j (15) i where, ij K , K , K , t = M gij K , K , K , t and 1-M = S , with M x k and S are an arbitrary constants. Following the same procedure as was used in obtaining (12), we get: ui u j ukX X x k kk kk kk h K , K , K j K , K , K ki ki ki ijk (16) Equation (15) and (16) are the spectral equations corresponding to the four-point correlations. To get a better picture of the of the first-order reactant of homogeneous dusty fluid turbulence decay in a rotating u u X X v x x k x k x k i j 2 2 R 2mki m Sf gij i k k k k k k hijk K , K , K ik k hijk K K K , K , K uiuk u j X X p ui X X 1 pu j X X xi x j 2 Four-point correlation and spectral equations: Again by taking the Navier-Stokes equations at p and p! and the concentration equations at p", p"! and following the same procedure as before, one can get the four-point correlations as: ui u j X X 2 32 Res. J. Math. Stat., 4(2): 30-38, 2012 system from its initial period to its final period, four-point correlations are to be considered. The same ideology could be applied to the concentration phenomenon. Here, we neglect the quintuple correlations since the decay faster than the lower-order correlations. As pointed out by Deissler (1958, 1960) when the quintuple correlations are neglected, the corresponding pressure-force terms which are related to them are also neglected. Under these assumptions, Eq. (15) and (16) give the solution as: 3 2i k k k k bi 2 3 3 D 2 1 N s 2 1 4 kD 2 F 2 1 1 t t0 2 1 N s 2 Ns2 Ns k 2 exp D N s kk 1 N s k 2 1 N s Sf 2 mki m t t0 exp 2 R t t0 D D (20) where, gij K , K , K , t gij K , K , K , t 0 exp D 2 N s k 1 N s k k 2 2 2 F exp 2 2 N s k k k k k k k k k k k k 2 R 2mki m Sf t t0 expression for ui uk X X r, r ij 0 0 (21) i Now, by taking r 0 in the expression for u X X r, r is performed, we obtain and comparing the result with the expression Xuk X r : : ij 1/2 g K K , K , K , t b and comparing it with the g K K , K , K , t dK ik K , K t t0 D s 2 and (17) N s = v / D . A r e l a t i o n betwe e n gij K , K , K , t0 and ij K , K can be found by taking r 0 in the ui uj X X r, r , r 0 whe r e , expression for expn dn, k 91 N k K k K . K dk (18) (22) Substituting Eq. (21) into (8), we obtain: Substituting this in to Eq. (13), we obtains: G 2 Dk 2 2 R G W t j 2 R 2mki m Sf D 1 N s K 2 K 2 2 N s K . K t D D D j i k k k k gij K K , K , K , t dK (23) where, G = 2Bk22 which with the help of Eq. (17), gives: and j 2 R 2mki m Sf D 1 N s K 2 K 2 2 N s K . K D D D j t 2i k k g K K , K , K , t k k ij a D 3 / 2 1 N s 0 3/ 2 0 j K , K , t0 j K , K , t0 exp D 1 N s k 2 k 2 t t0 3/ 2 Qf 2 2 N s K . K mki m t t0 D D (19) bi K , K bi K , K 1 N s 2i 5/ 2 D 3/ 2 3/ 2 2 4 kF w D1/2 1/ 2 t t0 1 N s 1/2 Ns 2 Ns k 2 exp D 2 N s kk 1 N s Now, the solution of Eq. (19) is: kk k K , K k K , K 0 2 R 2 mki m Qf t t0 D D D 3/ 2 Ns2 Ns k 2 exp D 2 N s kk 1 N s k 2 1 N s W 2ik 2 exp 2 R t t0 1 N s k 2 2mkiD m SfD t t0 dk 0 exp D 1 N s K 2 K 2 2 N s K . K 2 R 2mki m Qf t t0 D D D (24) In analogy with the turbulent energy spectrum function, the quantity G, in Eq. (23) can be called 33 Res. J. Math. Stat., 4(2): 30-38, 2012 N 2 N s k 11 s 7 1 1 Ns D1 N s t t0 concentration energy spectrum function and W, the energy transfer function, is responsible for the transfer of concentration from one wave number to another. In order to find solution completely and following Deissler (1958, 1960) we assume that: 2 2 ik k 0 K , K 0 K , K 0 k k k k 2 4 4 2 21 N 2 N 3s k 13 s 5 2 1 Ns 1 N s 2 N 2 s 1 1 Ns exp n2 dn exp 2 R t t0 0 (25) 0 It is very interesting that: and 8 7 2 3 i b K , K b K , K 3 D 2 1 N s 2 1 k 4 k 6 k 6 k 4 W dk = 0 0 This indicates that the expression for W satisfies the condition of continuity and homogeneity. Physically it was to be expected, since W is the measure of transfer of energy and the total energy transformed to all wave numbers is to be zero, which is what Eq. (26) gives. The linear Eq. (23) can be solved to give: where, >0 and >1 are arbitrary constants depending on the initial conditions. If these results are used in Eq. (24) and the integration is performed, we obtain: W 0 2 t t0 3 2 1 2N 3 D2 exp 2 Dk 5 2 1 1 11 9 3 2 t t0 2 D 2 21 N s 2 3 4 7 N s 6 6 f1 8 2 f1 9 F 3 2 N s N 2 N s k 10 x 7 1 D1 N s t t0 1 Ns 1 N 2 21 N 2 N 2 s k 12 s s 1 5 1 N s 2 t t 0 1 N s 2 1 Ns 0 2 N s Qf 2 exp 1 2 N s 2 mki m D D Ns 105k 6 15k 8 3 2 3 2 3 8 D N s t t0 1 N s 4 D N s t t0 21 0 Qf 2 exp 21 N s 2 mki m D D 7 2 N s 2 mki m Sf exp 2 D k t t0 D 2 D 1 N s 1 2N (27) 2 N 0 1 N s G exp 2 R t t0 D t t0 1 2 N s 1 N s 2 2 N 3 N k6 s s k8 N s D t t0 1 N s 1 N s 3 D2 2 where, J (k) = N0k is a constant of integration and can be obtained as by Corrsin (1951). Thus, by integrating the right-hand side of equation, we obtain: 2 Ns Ns 15k 4 3 5 2 2 2 1 N 1 N 2 s s 4 D N s t t0 t t0 2 R t t dt exp 2 Dk 2 R t t0 W s 1 N s 7 2 G J k exp 2 Dk 2 2 R t t0 1 2 N s 2 2mki m Qf exp D k t t0 N D D 1 s (26) 1 2 15 3 2 t t0 D 2 1 N s 2 7 105 6 5 11 24 N 2 s 8 N s 8 f 2 10 16 32 s Sf 2 f 3 12 2 f 3 14 exp 2 2 Ei 2 2 0.5772 mki m D D 3 t t0 2 D1 N s 4 1 2 N s 2mki m Sf ex D t t0 D D 1 N s 9 7 Ns 105k 15k 2 3 3 3 2 8 D N s t t0 1 N s 4 D N s t t0 1 2 21 N s 15 3 2t t1 D 2 21 N s 2 7 2 mki m Sf exp 1 2 N s 2 2 D D 34 Res. J. Math. Stat., 4(2): 30-38, 2012 105 8 2 10 23 12 498 14 3 30 630 8 N s 3 Sf 2 2 exp 2 2 mki m E 2 0.5772 D D i In a turbulent phenomenon, such as turbulent kinetic energy, we associate the so-called concentration energy with the fluctuating concentration, defined by the relation: 1 XX G k , t dk 2 31808 . 10 2 14 2.7178 10 2 16 13968 . 10 2 18 4.6204 10 3 20 11584 . 10 3 22 2.3139 10 4 24 5 26 55108 . 10 3 22 2.3139 10 4 24 The substitution of Eq. (28) and subsequent integration with respect to k leads to the result: 4 28 38589 . 10 11584 . 10 1 2 X exp 2 R t t0 2 23 5 A t t0 B t t0 exp R2 t t0 15 1 15 15 C t t0 2 D1 t t0 2 t t1 2 E t t0 1 29 15 2 2 F t t0 G t t0 t t1 exp R3 t t0 7 30 6.8898 10 15 N 2 s 2 N s 1 10 5 12 14 14 4 Ns 6 15 2 Sf 2 2 exp 2 2 mki m E 2 0.5772 D D i 8.6172 10 6 22 9.22057 10 7 24 8.9477 10 8 26 7.9374 10 9 28 6.4814 10 10 30 A 12 s 4 14 3 6.66926 10 7 26 8.6642 10 D 8.0290 10 6 24 8.4643 10 8 28 d 7.5495 10 9 30 Ei 2 2 0.5772 2.2654 10 , C cd , D1 ce, N s 2 1 N s 7 e 2 f3 h 1 16 10679 . 10 7 D 2 I 2 N s 2 , 1 N s 1 2 1 1 2 2 37.123111 N s 2 , f 9 D8 2 1 N s , g 105 2 Ns 1 6 75.90 2.52052 103 1 2 2 15 3 1 1 1 N 2 s 3 18 3.3996 10 9.0694 10 3 20 11099 . 10 3 22 3.7350 10 4 24 9 i1 1118 . 1 2 6 28 8.2388 10 7 30 8.47486 10 1 1 N s 2 D I 1 2 N s , 2 j1 1633 31808 . 10 2 4.0767 10 1 1 1 3561804 . 1 2 (28) 1 2.2386 101 3 11786 . 102 1 4 5.4148 102 1 5 2.02576 103 1 6 8.7048 1 7 31561 . 104 1 8 where, 2 D D6 9 1 14 4.444 10 0 R1 2 f3N 2 s 105 35 11 24 N s 8 N s 63 f 2 693 f 3 1808 f 3 415910 . 1 32 64 N s 256 64 N 2 s 64 N 3s 1 N 2 5 26 15 22 1 Sf 2 1 2 N s N s 14 exp 2 mki m D D 3 ,B 151 8 4.90805 10 5 22 N0 3 7 1 D2 22 2 c 4 20 31572 . 10 F cf gi1 k1m ht , G cf pr1 , 8.2505 1010 14 17495 . 10 2 16 3 18 (30) E cf gh gj1 k1l1 k1n pq ps t vw , Sf 2 2 exp 2 2 mki m E 2 0.5772 D D i This is the decay law of first order reactant in homogeneous dusty fluid turbulence in a rotating system, where, 5.4047 10 4 18 7.2369 10 5 20 11N 2 s 20 N s 2.0260 10 2 14 35487 . 10 3 16 10 N (29) t t1 k 2 , f 4 3 N 2 2 N 3 s 1 N s 1 3 s k1 15 40 N 2 s 2 N s 1 4 N 2 s 11N 2 s 20 N s f2 2 161 N s D 15 20 4 N f3 2 s 2 Ns 4 N 2 s 9 N 81 N s 3 2 s N s1 11 m 7.44691 2 20 N s 16 N s 2 n 35 , l 1 55 2.3510 10 135 6 N s 2 2 N s 1 163 12 1 2 1 1 N s 2 D 61 11 1631 2 215 1 N s I 1 2 N s 2 , 2 2.0261 5.3230 10 2 1 3 15 2 Res. J. Math. Stat., 4(2): 30-38, 2012 RESULTS AND DISCUSSION 13782 . 10 1 12 35063 . 10 1 1 3 8.7676 10 1 1 4 2.57710 1 1 5 5.23471 6 12538 . 1 7 2.9690 In Eq. (30) we obtained the decay law of first order reactant in homogeneous dusty fluid turbulence for fourpoint correlation in a rotating system after neglecting quintuple correlation terms. The equation contains the 101 8 p 396 11N s2 20 N s 10 N s12 4 q 1 3.0532 10 1 1 N s 1 1 N s 2 r1 10638 . 1 2 t t1 2 1 13 13 2 D terms 15 2 I 1 2 N s 2 , 2 s 1311 8.2504 2.6243 101 1 8.0509 101 2 1 3 2.3780 6.78561 4 18789 . 1 6 2 7 5.0688 10 1 13370 . 10 1 101 5 t 14219 . N s 1 1 N s 2 1 21 , t t 0 , t t 0 5 15/ 2 . Thus, the terms 1 11 2 3 1 2 5 X exp 2 R t t0 A t t0 2 B t t0 2 1 u 31886 . . 103 14443 102 t t0 2 D 2 1 N s 3/ 2 0 associated with the higher-order correlation die out faster than those associated with the lower-order ones; therefore, the assumption that the higher-order correlations can be neglected in comparison with lower-order correlations seems to be valid in our case. If the system is non-rotating and the fluid is clean (i.e., Sm = 0, f = 0) the Eq. (30) becomes: 3.4583 102 1 8 2 t t I 1 2 N s 2 , 2 15 15 1 15 C t t0 2 D1 t t0 2 t t1 2 E t t0 29 1 15 F t t0 2 G t t0 t t1 2 v 18102 . 102 1 2 N S 1 2 1 2 15 w 2.2653 10 1 160195 . 1 1 (31) 8.6664 10 1 2 4.3941 101 3 11293 . 102 1 4 8.7405 102 1 5 which is obtained by Kumar and Patel (1974). Here A, B, C, D1, E, F, G are an arbitrary constants. With R = 0 and the contaminant replaced by the temperature, the results agrees with the result obtained by Loeffler and Deissler (1960) for the decay of temperature fluctuation in homogeneous turbulence before the final period for threepoint correlations. For large times, the last terms become negligible and give the -3/2 power decay law for the final period. In figures, Eq. (30) represented by the curves y1, y2, y3 and (31) by y4, y5, y6 at t0 = .3, t1 = .5; t0 = .8, t1 = 1 and t0 = 1.3, t1 = 1.5, respectively the 2.6001 103 1 6 13013 . 104 1 7 38822 . 104 1 8 R1 21 N S 1 2 N s 5 2 9 5 N s 7 N s 6 16 161 2 N s f 1 N s 1 2 N s 2 105 f1 N s 21 11 321 2 N s 2 2 1 N s 2 5 135 . . ...2n 9 n 2n n 0 n! 2 N s 1 2 1 N s Sf 2mki m Qf 2 , R mki m D D 3 D D 1 21 2 N s , R2 Y4, y5, y6 for Eq.(31) at t0 = 0.3, t1 = 0.5, t0 = 0.8 t1 = 1 and t0 = 1.3, t1 = 1.5, respectively y6 I , exp 2 2 0 2 14 Decay of total energy of homo 2 .turbulence = X and dk exp Ei 2 2 The first term of Eq. (30) corresponds to the concentration energy for two-point concentration; the second term represents first order reactant in homogeneous dusty fluid turbulence in a rotating system for three-point correlation. The expression exp[!R2(t!t0)] represents the dusty fluid turbulence in a rotating system for three-point correlation; the expression exp[!R3(t!t0)] and the remainder are due to dusty fluid turbulence for four-point correlation in a rotating system. 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 y4 y5 y1 y3 y2 Y1, y2, y3 for Eq.(30) at t0 = 0.3, t1 = 0.5, t0 = 0.8 t1 = 1 and t0 = 1.3, t1 = 1.5, respectively 1.8 2.0 2.2 2.4 2.6 2.8 3.0 Approximation of time = t 3.2 3.4 Fig. 1: Comparison between Eq. (30) and (31) if R = 0.025 36 Res. J. Math. Stat., 4(2): 30-38, 2012 CONCLUSION Decay of total energy of homo 2 .turbulence = X Y1, y2, y3 for Eq.(30) at t0 = 0.3, t1 = 0.5, t0 = 0.8 t1 = 1 and t0 = 1.3, t1 = 1.5, respectively 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 From the above figures and discussions, this study shows that the chemical reaction rate increases than the concentration fluctuation to decay more decreases and vice versa. At the chemical reaction rate R = 0 causes the concentration fluctuation of decay more rapidly than they would for (R…0) non pure mixing homogeneous dusty fluid turbulence. Also we conclude that due to the effect of rotation of homogeneous dusty fluid turbulence in the flow field of the first order chemical reaction for fourpoint correlation the turbulent energy decays more slowly than the energy decay for the first order reactant in homogeneous turbulence. Y4, y5, y6 for Eq.(31) at t0 = 0.3, t1 = 0.5, t0 = 0.8 y6 t1 = 1 and t0 = 1.3, t1 = 1.5, respectively y5 y3 y4 y2 y1 0 1.8 2.2 2.0 2.4 2.6 3.0 2.8 Approximation of time = t 3.4 3.2 Fig. 2: omparison between Eq. (30) and (31) if R = 0.5 ACKNOWLEDGMENT Decay of total energy of homo 2 .turbulence = X Y1, y2, y3 for Eq.(30) at t0 = 0.3, t1 = 0.5, t0 = 0.8 t1 = 1 and t0 = 1.3, t1 = 1.5, respectively 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 y5 y4 y3 This study is supported by the research grant under the ‘National Science and Information and Communication Technology’ (N.S.I.C.T.), Bangladesh and the authors (Bkar, Azad) acknowledge the support. The authors also express their gratitude to the Department of Applied Mathematics, University of Rajshahi for providing us all facilities preparing this study. Y4, y5, y6 for Eq.(31) at t0 = 0.3, t1 = 0.5, t0 = 0.8 y6 t1 = 1 and t0 = 1.3, t1 = 1.5, respectively y2 REFERENCES y1 1.8 2.0 2.2 2.4 2.6 2.8 3.0 Approximation of time = t 3.2 Aziz, M.A., M.A.K. Azad and M.S.A. Sarker, 2009. First order reactant in Magneto-hydrodynamic turbulence before the final period of decay for the case of multipoint and multi-time in a rotating system. Res. J. Math. Stat., 1(2): 35-46. Aziz, M.A., M.A.K Azad and M.S.A. Sarker, 2010. First oder reactant in MHD turbulence before the final period of decay for the case of multi-point and multitime in a rotating system in presence of dust particle. Res. J. Math. Stat., 2(2): 56-68. Batchelor, G.K., 1953. The Theory of Homogeneous Turbulence, Cambridge University Press, Cambridge, pp: 79. Chandrasekhar, S., 1951. The invariant theory of isotropic turbulence in magneto-hydrodynamics. Proc. Roy. Soc., London, A204: 435-449. Corrsin, S., 1951. On the spectrum of isotropic temperature fluctuations in isotropic turbulence. J. Apll. Phys., 22: 469-473. Deissler, R.G., 1958. On the decay of homogeneous turbulence before the final period. Phys. Fluid, 1: 111-121. Deissler, R.G., 1960. A theory of decaying homogeneous turbulence, Phys. Fluid, 3: 176-187. Kumar, P. and S.R. Patel, 1974. First order reactant in homogeneous turbulence before the final period of decay. Phys. Fluids, 17: 1362-1368. 3.4 Fig. 3: Comparison between Eq. (30) and (31) if R =8 Decay of total energy of homo 2 .turbulence = X Y4, y5, y6 for Eq.(31)at t0 = 0.3, t1 = 0.5, t0 = 0.8 t1 = 1 and t0 = 1.3, t1 = 1.5, respectively 5.0 y6 4.5 y4 y5 4.0 y3 3.5 3.0 y2 y1 2.5 2.0 1.5 1.0 Y1, y2, y3 for Eq.(30) at t0 = 0.3, t1 = 0.5, t0 = 0.8 0.5 t1 = 1 and t0 = 1.3, t1 = 1.5, respectively 0 1.8 2.0 2.2 2.4 2.6 2.8 3.0 Approximation of time = t 3.2 3.4 Fig. 4: Comparison between Eq. (30) and (31) if R = 0 snergy decays more slowly. For R2 = 0.25 and R3 = 0.5, the comparison between the Eq. (30) and (31) are shown in Fig. 1, 2, 3 and 4 corresponding to the values R = 0.025, 0.5, 0.8 and 0, respectively, the energy decays slowly than non rotating clean system which indicates in the figures clearly. 37 Res. J. Math. Stat., 4(2): 30-38, 2012 Sarker, M.S.A. and M.A. Islam, 2001. Decay of dusty fluid MHD turbulence before the final period in a rotating system. J. Math and Math Sci., 16: 35-48. Sultan, S., 2008. Energy decay law of dusty fluid turbulent flow in a rotating system. J. Eng. Appl. Sci., 3(2): 166-174. Kumar, P. and S.R. Patel, 1975. First order reactant in homogeneous turbulence before the final period for the case of multi-point and multi-time. Int. J. Eng. Sci., 13: 305-315. Loeffler, A.L and R.G. Deissler, 1961. Decay of temperature fluctuations in homogeneous turbulence before the final period. Int. J. Heat Mass Transfer, 1: 312-324. Sarker, M.S.A and N. Kishore, 1991. 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