Research Journal of Applied Sciences, Engineering and Technology 5(2): 585-595, 2013 ISSN: 2040-7459; E-ISSN: 2040-7467 © Maxwell Scientific Organization, 2013 Submitted: May 19, 2012 Accepted: June 06, 2012 Published: January 11, 2013 First-Order Reactant in Homogeneous Turbulence Prior to the Ultimate Phase of Decay for Four-Point Correlation in Presence of Dust Particle M.A. Bkar PK, M.A.K. Azad and M.S. Alam Sarker Department of Applied Mathematics, University of Rajshahi, Rajshahi-6205, Bangladesh Abstract: In this study, following Deissler’s approach the decay in homogeneous turbulence at times preceding to the ultimate phase for the concentration fluctuation of a dilute contaminant undergoing a first-order chemical reaction for the case of four-point correlation in presence of dust particle is studied. Two, three and four-point correlation equations have been obtained and the correlation equations are converted to spectral form by their Fourier-transforms. 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 of homogeneous dusty fluid turbulent flow for the concentration fluctuations ahead of the ultimate phase for four-point correlation has been obtained and is shown graphically. Keywords: Deissler’s method, dust particle, fourier-transform, navier-stokes equation, turbulent flow et al. (2010) also extended their previous problem in presence of dust particle. Corrsin (1951) obtained on the spectrum of isotropic temperature fluctuations in isotropic turbulence. Azad et al. (2011) studied the statistical theory of certain distribution functions in MHD turbulent flow for velocity and concentration undergoing a first order reaction in a rotating system. 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 fluid turbulence prior to the ultimate phase of decay for four-point correlation in presence of dust particle. Through this study we would like to find the decay law of first order reactant in homogeneous fluid turbulence in presence of dust particle. Presently we shall try to show in this study the chemical reaction rate R = 0 causes the concentration fluctuation of decay in presence of dust particle is more rapidly than for the reaction rate R 0 in the absence of dust particle f = 0. The comparison between the effects of the chemical reaction in the homogeneous fluid turbulence and the dust particles are graphically discussed. It is observed that the chemical reaction rate increases than the concentration fluctuation to decay more decreases and vice versa. 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. Deissler (1958, 1960) developed a theory ‘on the decay of homogeneous turbulence before the final period.’ Using Deissler’s theory, Kumar and Patel (1974) studied the first-order reactant in homogeneous turbulence before the final period of decay. 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 MHD turbulence before the final period for the case of multi-point and multi-time. Islam and Sarker (2001) also obtained the first order reactant in MHD turbulence before the final period of decay for the case of multi-point and multi-time. 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 MATERIALS AND METHODS Basic equation: The differential equation governing the concentration of a dilute contaminant undergoing a first-order chemical reaction in homogeneous dusty fluid turbulence could be written as: Corresponding Author: M.A. Bkar PK, Department of Applied Mathematics, University of Rajshahi, Rajshahi-6205, Bangladesh 585 Res. J. Appl. Sci. Eng. Technol., 5(2): 585-595, 2013 u i u i 2ui uk D Ru i f (ui vi ) t x k x k x k (1) ˆ ˆ ˆ XX (r) ( K , t ) exp[ i ( K . rˆ )] d K (5) where, ui ( ) = A random function of position and time at a point p uk ( , t) = The turbulent velocity R = The constant reaction rate D = The diffusivity t = The time ƒ = kN/p, dimension of frequency N, Constant number density of dust particle ms = (4/3) Rs3 ps is the mass of single spherical dust particle of radius Rs ps = The constant density of the material in dust particle ui = The turbulent velocity component vi = The dust particle velocity component xk = 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. Two-point correlation and spectral equations: Under the restrictions that the turbulence and the concentration fields are homogeneous, the local mass transfer has no effect on the velocity field; 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: 2 uk D R t x k x k x k XX t uk XX x k D 2 XX x k x k (4) where, X′j is the fluctuating concentration at the point p′ ( ) and the point p′ is at point a distance r from the point p. The symbol 〈 〉 is the ensemble average. Putting the Fourier transforms: (6) (7) into Eq. (4), one obtains: ˆ ( Dk 2 2 R ) ik k [ k ( Kˆ , t ) ‐ K ( K , t ) ] (8) t Three-point correlation and spectral equations: Taking the Navier-Stokes equations for a first-order chemical reaction in homogeneous dusty fluid turbulence at p is: u i 2ui u i uk D Ru i f (u i vi ) t x k x k x k and the fluctuation equations at p′&p′′one can find the three-point correlation Equation as: ui X X t u k u k X X x k ui u k X X ui u kX X xk xk 2 u i X X 1 p X X xi x k x k 2 2 D x k x k x k x k (3) R XX ˆ ˆ ˆ k ( K , t ) exp[ i ( K .rˆ )] d K ˆ ˆ ˆ ˆ u k XX (r) k ( K , t ) exp[ i ( K .r )] d K Subtracting the mean of (2) from Eq. (2), we obtain: where, X( , t) is the fluctuation of concentration about the mean at a point p( ) and time t. The two-point correlation for the fluctuating concentration can be written, as: (2) X X 2X uk D RX t x k x k x k u k XX (r) f u i u i X X 2 R u i X X X X v i X X (9) Using the transformations: , , r r x x x rk xk k k k k k In order to convert Eq. (9) to spectral form, using six-dimensional Fourier transforms (Kumar and Patel, 1974) and: v i X X 586 i ( Kˆ , Kˆ , t ). exp[ i ( Kˆ .rˆ Kˆ .rˆ ) d Kˆ d Kˆ ] Res. J. Appl. Sci. Eng. Technol., 5(2): 585-595, 2013 with the fact that u i u k X X = ui uk X X 2 2 u i u j X X D x k x k x k x k one can write Eq. (9) in the form: j t 2 R u i u j X X 2 [ Kˆ Kˆ D Kˆ Kˆ 2 R Qf ] j i ( k k k k ) jk i ( k k k k ) jk 1 xi xk xk rk rk rk , , xk xk xk rk xk rk 2 1 pX X xi xi (11) and nine-dimensional Fourier transforms (Kumar and Patel, 1974) and: In Fourier space it can be written as: ( k k k k ) ik 1 (14) In order to convert Eq. (14) to spectral form, using the transformations: and Q 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: f u i u j X X v i u j X X i ( k j k j ) (10) where, i ( Kˆ , Kˆ , t ) = L j ( Kˆ , Kˆ , t ) and 1-L = Q ,with L 2 u i u k X X v i u j X X ( rˆ , rˆ , rˆ ) (ki ki) (12) ij ( Kˆ , Kˆ , Kˆ , t ) exp[ i ( Kˆ .rˆ Kˆ .rˆ Kˆ .rˆ ) d Kˆ d Kˆ d Kˆ Substituting this into Eq. (10), we obtain: j t and with the fact that: 2 [ Kˆ Kˆ D Kˆ Kˆ 2 R Qf ] j i ( k k k k ) jk u ku i u j X X ( rˆ , rˆ , rˆ ) 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: u i u j X X t u ku i u j X X ( rˆ , rˆ , rˆ ) (13) u i u k u j X X x k Eq. (14) can be written as: g ij 2 [ Kˆ Kˆ Kˆ Kˆ 2 t D Kˆ Kˆ 2 2 R Sf ] g ij u j u ku i X X i ( k k k k k k )[ h ijk ( Kˆ , Kˆ , Kˆ ) x k ik k [ h ijk ( Kˆ Kˆ Kˆ , Kˆ , Kˆ )] u i u j u k X X x k X u i u j u k X i ( k k k k) h ijk ( Kˆ , Kˆ , Kˆ ) x k p u i X X 1 p u j X X [ ] xi x j 2 2 x k x k xk xk u i u j X X 1 [ ( k i k i k i) j ( Kˆ , Kˆ , Kˆ ) k j i ( Kˆ Kˆ Kˆ , Kˆ , Kˆ )] (15) where, ij ( , ′, ′′′, t) = M gij( , ′, ′′′, t) and 1-M = S, with M and S are an arbitrary constants. 587 Res. J. Appl. Sci. Eng. Technol., 5(2): 585-595, 2013 Following the same procedure as was used in obtaining (12), we get: j ( Kˆ , Kˆ , Kˆ ) ( k k k k k ) k hijk ( Kˆ , Kˆ , Kˆ ) ( k i k i k i) a 3 / 2 (1 N s ) 3 / 2 (t t 0 ) 3 / 2 N s (2 N s )k 2 2 N s kk D[ (1 N s ) exp (t t 0 ) 2 R Qf (1 N ) k 2 ] s D D (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 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: D 3/ 2 Now, the solution of Eq. (19) is: j ( Kˆ , Kˆ , t 0 ) j ( Kˆ , Kˆ , t 0 ) exp 2 i ( k k k k ) b i 3 / 2 D 3 / 2 (1 N s ) 3 / 2 [ 4 kD 1 / 2 F ( ) 2 ] 1/ 2 (t t0 ) (1 N s ) 1 / 2 ƒ/| exp 1 2 ′ (20) where, F ( ) exp( 2 ) exp( n 2 ) dn 0 (t t 0 ) D k 91 N s ) with the expression for ui u k X X (rˆ, rˆ) : (18) 2 2 where, Ns = v/D. A relation between gij( , ′, ′′′, t0) and ′ij( , ′) can be found by taking ′′ = 0 in the expression for u i u j X X (rˆ, rˆ , rˆ ) and comparing it 0 [ g ij ( Kˆ , Kˆ , Kˆ , t 0 ) exp{ D[2 N s k 2 (1 N s )(k 2 k 2 ) ik ( Kˆ , Kˆ ) g ij (Kˆ Kˆ , Kˆ , Kˆ , t )dKˆ K 2 ) 2 N s Kˆ . Kˆ Qf 2R ]( t t 0 ) D D D [( 1 N s )( K g ij ( Kˆ , Kˆ , Kˆ , t ) 2 N s ( k k k k k k k k k k k k)] 2 R Sf }( t t 0 ) (17) (19) 1/ 2 and [ g ij ( Kˆ Kˆ , Kˆ , Kˆ , t0 )]0 bi (21) Substituting this in to Eq. (13), we obtains: j 2 R Sf ] j D[(1 N s )( K K ) 2 N s Kˆ .Kˆ t D D 2 2 i ( k k k k ) g ij ( Kˆ Kˆ , Kˆ , Kˆ , t ) d Kˆ , Now, by taking rˆ 0 in the expression for u X X ( rˆ, rˆ is performed, we obtain and comparing the result with the expression X u k X (rˆ ) : k ( Kˆ ) which with the help of Eq. (17), gives: k ( Kˆ . Kˆ ) d k (22) Substituting Eq. (21) into (8), we obtain: j 2 R Sf D[(1 N s )( K 2 K 2 ) 2 N s Kˆ .Kˆ ] j D D t ˆ ˆ ˆ ˆ 2i ( k k k k )[ g ij ( K K , K , K , t 0 )] 0 G ( 2 Dk t 588 2 2 R )G W (23) Res. J. Appl. Sci. Eng. Technol., 5(2): 585-595, 2013 where, G 2 k 2 and: 1 2N s exp{ D [ 1 Ns W 2 ik 2 exp[ 2 R ( t t 0 )] { k k [ k ( Kˆ , Kˆ ) k ( Kˆ , Kˆ ) ]0 exp{ D [(1 N s )( k 2 k 2 ) 2 N s Kˆ . Kˆ ( Qf / D )]( t t 0 )} 2i D 3 / 2 (1 N s ) 3 / 2 [ [b ( Kˆ , Kˆ ) b ( Kˆ , Kˆ )] i ( 2 ) 2 ik k 0 ( Kˆ , Kˆ ) 0 ( Kˆ , Kˆ ) [ 105 k 7 8 D N 2 s (t t 0 ) 3 15 k 9 3 2 4 D N s (t t 0 ) Ns [ 7 1 N s [ 1/ 2 N s 2 (t t 0 ) Sf ( )]( t t 0 ) D 3 Ns 1 N s 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: 0 3/2 2 1]} 0 1 ( k 4 k 6 k 6 k 4 ), W 2 Ns N 2 s k 12 5 ] [ 2 1 ( ) N t t 1 N s 0 s 2 1 1 / 2 N s ( t t 0 ) 3 / 2 D (1 N s ) 4 { And D 2 1 2N s exp D [ 1 Ns 0 2 8 7 / 2 i b ( Kˆ , Kˆ ) b ( Kˆ , Kˆ ) (1 N s ) 3 / 2 15 k 8 3 2 4 D N s (t t 0 ) 21 N s 2 1 N s 2 Sf k ( )]( t t 0 )} 2 D N s k 10 1] 1 ( ) D N t t s 0 Ns [ 7 1 N s 0 ( k k k k ) 3/2 8 ]k } 105 k 6 8 D 3 N 2 s (t t 0 ) 3 Ns 1 Ns (24) In analogy with the turbulent energy spectrum function, the quantity G, in Eq. (23) can be called 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: 4 2 (t t 0 ) 7 / 2 D 3 / 2 (1 N s ) 7 / 2 Ns exp{ 2 D [ 1 N s N s (2 N s )k 2 2 N s kk (1 N s ) 4 3 Ns 1 Ns 1 1 / 2 N s { (1 N s ) k 2 ( Sf / D )]( t t 0 ) d k } 2 Ns [5 1 N s i 2 4 kF ( w ) D 1 / 2 ] (t t 0 ) 1 / 2 (1 N s ) 1 / 2 exp{ D [ Ns 1 N s Ns 3 k6 ] [ 2 N s D (t t 0 ) 1 N s 5/2 15 k 4 2 4 D N 2 s (t t 0 ) 2 2 k ( Qf / D )]( t t 0 )} 21 2 D 3 / 2 (1 N s ) 5 / 2 0 589 Ns 1 N s exp( 2 1] 2 N s k 11 1 ( ) D N t t s 0 N 3 s k 13 5 ] 1 N s 2 Ns [ 1 N s n 2 ) dn } exp[ 2 R ( t t 0 )] 2 1] (25) Res. J. Appl. Sci. Eng. Technol., 5(2): 585-595, 2013 exp [(1 2 N s ) It is very interesting that: W dk = 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: exp ( 2 Dk W 2 2 2 R )( t t 0 ) 2 R )( t t 0 ) exp ( 2 Dk 2 exp[( 2 2 ) ( Sf / D )][ E i ( 2 2 ) 0 . 5772 ] 3 . 1808 10 2 14 2 . 7178 10 2 16 1 .3968 10 2 18 4 .6204 10 3 20 (27) 1.1584 10 3 22 2.3139 10 4 24 3.8589 10 5 26 5.5108 10 4 28 2 R )( t t 0 ) dt 1.1584 10 3 22 2.3139 10 4 24 2 where, J (k) N 0 k is a constant of integration and 6.8898 10 7 30 ... can be obtained as (Corrsin, 1951). Thus, by integrating the right-hand side of equation, we obtain: 2 G = exp[ 2 R (t t ) N 0 (1 N s ) 0 D (t t 0 ) exp[ 2 (1 N s ) 2 ( 2 ( Sf / D ) ] 105 8 2 10 23 12 498 14 3 30 630 8N s 3 (26) G J ( k ) exp ( 2 Dk 2 15( N 2 S 2 N s 1) 10 5 12 14 14 exp 4N s 6 15 2 [( 2 2 ) ( Sf / D )][ E i ( 2 2 ) 0 . 5772 ] 2.0261 10 2 14 3.5487 10 3 16 Qf )] D 5.4047 10 4 18 7.2369 10 5 20 0 1 / 2 N s 2 (t t 0 ) D 11 / 2 2 (1 N s ) 3 / 2 8.6172 10 6 22 9.22057 10 7 24 9/2 8.9477 10 8 26 7.9374 10 9 28 exp[ (1 2 N s ) 2 Qf ( )] D 6.4814 10 10 30 ... 3 4 7 N s 6 6 f 1 8 2 f 1 9 F ( ) 3 2N s [( 2 2 ) ( Sf / D )][ E i ( 2 2 ) 0.5772 ] 1 1 / 2 7 2 ( t t 0 ) D 15 / 2 (1 N s ) 3 / 2 8.2505 10 2 14 1.7495 10 2 16 105 6 5 (11 24 N 2 s 8 N s ) 8 f 2 10 32 16 f 3 2 f 3 12 14 3.1572 10 3 18 4.90805 10 4 20 6.66926 10 5 22 8.0290 10 6 24 exp( 2 ) 2 [ E i ( 2 ) 0 . 5772 ] ( Sf / D ) 8.6642 10 7 26 8.4643 10 8 28 7.5495 10 9 30 ... (1 2 N s ) N 3 s 14 exp[( 2 ) ( Sf / D )] 2 4 11 N 2 s 20 N s 10 N s 12 14 exp 3 2 1 Ns 15 / 2 2 (t t1 ) D 2 (1 N s ) 3 / 2 1/ 2 7 590 Res. J. Appl. Sci. Eng. Technol., 5(2): 585-595, 2013 [ E i ( 2 2 ) 0.5772 ] E cf ( gh gj1 k1l1 k1n pq ps t vw ) 2.2654 10 1 14 1.0679 10 1 16 F cf ( gi1 k1 m h t ), G cf pr1 3.3996 10 3 18 9.0694 10 3 20 1.1099 10 3 22 3.7350 10 4 d Ns 7/2 (1 N s ) 105 35(11 24 N 2 s 8 N s ) 63 f 2 32 64 N s 8N 2 s 693 f 3 1808 f 3 41 .5910 f 3 N 1 256 64 N 3 s (1 N s ) 2 4 (t t1 ) k 2 2 , f1 (3N s 2 N s 3) 3 (1 N s ) 15 40 N s (2 N s 1) 4 N s (11N f 2 16(1 N s ) 2 D 2 D 2 15 / 2 (28) where, 2 D 8 24 4.444 10 5 26 8.2388 10 6 28 8.47486 107 30 ... 15 1 c 2 2 s 7 2 S 1 e 2 f3 20 N s ) D 2 I ( 2 N s 2 , ) 2 1 (1 N s ) 2 1 2 1 37.12311 1 N s 2 , g = 105 f 9 2Ns D 8 2 (1 N s ) 15 20(4 N 2 s 2 N s ) 4 N 2 s (9 N 2 s 20 N s ) 16 N 2 s f 3 8(1 N s )3 9 In a turbulent phenomenon, such as turbulent kinetic energy, we associate the so-called concentration energy with the fluctuating concentration, defined by the relation: h= 1 6 75 .90 2.52052 10 3 1 2 2 15 3 1 1 (1 N s ) 2 1 1 2 XX G ( k , t ) dk i1 1 .118 1 (29) (1 N s ) 2 I [(1 2 N s ) , 2 ] D 9 2 j1 The substitution of Eq. (28) and subsequent integration with respect to k leads to the result: 163 1 3 1 (3.1808 10 2 4.0767 10 1 1 3.561804 1 3 1 X 2 At t 32 B t t 5 exp[ R (t t )] 0 0 2 0 15 1 15 15 2 2 2 C t t D t t t t E t t 0 1 0 1 0 29 1 15 F t t0 2 G t t0 t t1 2 exp[ R3 (t t0 )] 6 2.02576 103 1 8.7048 1 N0 3 7 1 D2 22 2 8 135(6 N s 2 N s 1) , 1 55 l1 N s1 2 6 1 2 k1 11 2 . 3510 10 3 163 1 2 2 15 (1 N s ) , B 0 R1 , C cd , D1 ce, D 7 3.1561 10 4 1 ...) (30) This is the decay law of first order reactant in homogeneous turbulence in presence of dust particle, where, A 4 2.2386 10 1 1.1786 10 2 1 5.4148 10 2 1 = exp[ 2 R ( t t 0 ) 2 11 m = 7 .4469 1 2 6 591 15 2 2 5 Res. J. Appl. Sci. Eng. Technol., 5(2): 585-595, 2013 (1 N s ) D 1 2 I [(1 2 N s ) 2 , 2 ] 4 1.1293 10 2 1 8.7405 10 2 1 2.6001 10 3 1 n = 163 (2.0261 5.3230 10 2 1 1 12 6 5 1.3013 10 4 1 7 8 3.8822104 1 ...) 1.3782 10 1 1 3.5063 10 1 1 2 8.7676 10 1 1 5.2347 1 6 4 2.57710 1 1 1.2538 1 7 3 R1 5 2.9690 10 1 8 ...) p = 396 (11 N s 2 20 N s 10 ) N s 1 2 13 2 q = 1 3 .0532 10 1 (1 N s ) 4 r1 1 .0638 1 13 2 (1 N s ) (t t1 ) D 1 2 9 5N s (7 N s 6) 2(1 N S )(1 2N s ) 5 / 2 16 16(1 2N s ) f N (1 2 N s ) 5 / 2 105 f1 N s 121 / s2 32(1 2 N s ) 2 (1 N s )11 / 2 1.3.5...( 2 n 9) ] 1 2(1 2 N s ) 2n (1 N s ) n n 0 n! ( 2 N s 1) 2 15 2 R 2 (Qf / D ) R3 (Sf / D) 1 2 f = constant number density dust particle and I [(1 2 N s ) , ] 2 2 I [ 2 , 2 ] S = 13 1 1 8.2504 3 4 1.3370 10 2 1 8 ...) 3.4583 10 2 1 11 2 t 1 .4219 N s 1 (1 N s ) 2 7 1 2 u = 3.1886 10 3 1.4443 10 2 (t t 0 ) 2 1 1 D 2 (1 N s ) 1 2 I [(1 2 N s ) 2 , 2 ]} 1 2 v = 1.8102 10 2 (1 2 N S ) 1 15 2 w = ( 2.2653 10 1 1.60195 1 1 8.6664 10 1 2 4.3941 10 1 3 14 exp( 2 ) E i ( 2 )] dk RESULTS AND DISCUSSION 2.3780 1 6.7856 1 1.8789 10 1 6 exp( 2 ) [ 0 2.6243 10 1 1 8.0509 10 1 2 5.0688 10 1 1 5 The first term of Eq. (30) corresponds to the concentration energy for two-point concentration; the second term represents first order reactant in homogeneous fluid turbulence in presence of dust particle for three-point correlation. The expression exp[ R2 (t t 0 )] represents the dusty fluid turbulence for three-point correlation; the expression exp[R3 (t t 0 )] and the remainder are due to fluid turbulence in presence of dust particle for four-point correlation. In Eq. (30) we obtained the decay law of first order reactant in homogeneous dusty fluid turbulence for four-point correlation after neglecting quintuple correlation terms. The equation contains the terms (t t 0 ) 3 / 2 , (t t 0 ) 5 , (t t 0 ) 15 / 2 . Thus, the terms 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 lowerorder correlations seems to be valid in our case. If the fluid is clean (i.e., f 0) the Eq. (30) becomes: 592 Res. J. Appl. Sci. Eng. Technol., 5(2): 585-595, 2013 5 Decay of total energy of homo.turbulence=X2 4.5 y6 4 y5 3.5 y2 3 y4 y1 2.5 2 1.5 y1,y2,y3 of Eq.(30) at t0=.3,t1=.5; t0=.8,t1=1 and t0=1.3,t1=1.5 respectively 1 y4,y5,y6 of Eq.(31) at t0=.3,t1=.5; t0=.8,t1=1 and t0=1.3,t1=1.5 respectively 0.5 0 1.8 2 2.2 2.4 2.6 2.8 Approximation of time=t Fig. 1: Comparison between Eq. (30) and (31) if R = 0.25 g p 5 q( 4.5 Decay of total energy of homo.turbulence=X2 y3 ) 3 q( 3.2 3.4 ) y3 y6 4 y1,y2,y3 of Eq.(30) at t0=.3,t1=.5; t0=.8,t1=1 and t0=1.3,t1=1.5 respectively 3.5 y2 3 y5 y4,y5,y6 of Eq.(31) at t0=.3,t1=.5; t0=.8,t1=1 and t0=1.3,t1=1.5 respectively 2.5 y1 2 y4 1.5 1 0.5 0 1.8 2 2.2 2.4 2.6 2.8 Approximation of time=t Fig. 2: Comparison between Eq. (30) and (31) if R = 0.5 593 3 3.2 3.4 Res. J. Appl. Sci. Eng. Technol., 5(2): 585-595, 2013 5 y3 Decay of total energy of homo.turbulence=X2 4.5 y6 4 y2 3.5 y5 3 y1 2.5 y4 2 1.5 1 0.5 0 y4,y5,y6 of Eq.(31) at t0=.3,t1=.5; t0=.8,t1=1 and t0=1.3,t1=1.5 respectively y1,y2,y3 of Eq.(30) at t0=.3,t1=.5; t0=.8,t1=1 and t0=1.3,t1=1.5 respectively 1.8 2 2.2 2.4 2.6 2.8 Approximation of time=t 3 3.2 3.4 Fig. 3: Comparison between Eq. (30) and (31) if R = 0 1 X 2 = exp[ 2 R ( t t 0 ) ] 2 [ At t 0 3 2 B t t 0 5 turbulence than clean fluid which indicates in the figures clearly. CONCLUSION 15 15 1 C t t 0 2 D1 t t 0 2 t t1 2 29 1 ] 15 15 E t t 0 F t t 0 2 G t t 0 t t1 2 (31) this is obtained by Kumar and Patel (1974). Here A, B, C, D1, E, F, G are constants which can be determined. With R = 0 and the contaminant replaced by the temperature, the results show complete argument with the result obtained by Loeffler and Deissler (1961) for the decay of temperature fluctuation in homogeneous turbulence before the final period up to three-point 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 and y6, respectively. For R2 0.25 and R3 0.25 , the comparison between the Eq. (30) and (31) are shown in Fig. 1, 2 and 3 corresponding to the values R = 0.025, 0.5 and 0, respectively, the energy decays rapidly in presence of dust particle of homogeneous fluid From the figures and discussions, this study shows that the terms associated with the higher-order correlations die out faster than those associated with the lower-order ones and if the chemical reaction rate increases than the concentration fluctuation to decay more decreases and vice versa. At the chemical reaction rate R = 0 of homogeneous fluid turbulence in presence of dust particle causes the concentration fluctuation of decay more rapidly than they would for the chemical reaction rate R 0 and f = 0. Also we conclude that due to the effect of homogeneous turbulence in the flow field of the first order chemical reaction for four-point correlation in presence of dust particle prior to the ultimate phase of decay, the turbulent energy decays more rapidly than the energy decay for the first order reactant in homogeneous turbulence before the final period. ACKNOWLEDGMENT the 594 This study is supported by the research grant under ‘National Science and Information and Res. J. Appl. Sci. Eng. Technol., 5(2): 585-595, 2013 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 regarding this study. REFERENCES Azad, M.A.K., M.A. Aziz and M.S.A. Sarker, 2011. Statistical theory of certain distribution functions in MHD turbulent flow for velocity and concentration undergoing a first order reaction in a rotating system. Bangladesh J. Sci. Ind. Res., 46(1): 59-68. Aziz, M.A., M.A.K. Azad and M.S. Alam Sarker, 2009. First order reactant in Magneto-hydrodynamic turbulence before the final period of decay for the case of multi-point 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. Alam Sarker, 2010. 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 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. Islam, M.A. and M.S.A. Sarker, 2001. First-order reactant in MHD turbulence before the final period of decay for the case of multi-point and multi-time. Indian J. Pure Appl. Math., 32: 1173-1184. Kumar, P. and S.R. Patel, 1974. First-order reactant in homogeneous turbulence before the final period of decay. Phys .Fluids, 17: 1362-1368. Kumar, P. and S.R. Patel, 1975. On first-order reactants in homogeneous turbulence, 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 Trans., 1: 312-324. Sarker, M.S.A. and N. Kishore, 1991. Decay of MHD turbulence before the final period, Int. J. Eng. Sci., 29: 1479-1485. Sarker, M.S.A. and M.A. Islam, 2001. Decay of MHD turbulence before the final period for the case of multi-point and multi-time. Indian J. Pure Appl. Math., 32: 1065-1076. 595