FLOW AROUND A CYLINDER - istiarto

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– 4.46 – Fig. 4.11 Surface correction: (a) displacement of the vertices of the surface boundary cells, (b) modification of the variables at the new cell centers. � compute the upper limit of the surface correction based on the cell thickness: �h z � � � �1 �zPT , 0 ≤ �1 ≤ 1 � compute the displacement of the boundary node T by: �h � �h p � � �h � min 1, min allcells z � � �h p �� since a cell is defined by its vertices, �h at T needs to be distributed over the vertices, Te, Tw, Tn, Ts (see Fig. 4.11a); linear interpolation is used � move the cell vertices of the free-surface boundary cells according to the new coordinates of Te, Tw, Tn, Ts
– 4.47 – � reconstruct the mesh, maintain the number of cells in the vertical and their relative positions to the local depth � use linear interpolation to get variables at the new cell centers (see Fig. 4.11b) in order to maintain the continuity: �z uP �� uP �z �� , v �z P �� vP �z �� , wP �� w P, �z kP �� kP �z �� , � �z P �� P �z �� , pP �� pP � � gz �h � continue the computation to the next time level 4.6 Solution procedures 4.6.1 Spatial discretisation Applying the discretized governing equations, Eqs. 4.52 and 4.68 requires spatial discretisation of the computational domain. The domain is divided into Ni–2, Nj–2, and Nk–2 cells in the x-, y-, z-directions, respectively, from which there are Ni, Nj, and Nk nodes (interior, boundary, and dummy nodes) in the corresponding directions. A typical spatial discretisation is shown in Fig. 4.12. The cell and node are denoted by a single index; the cells are indexed by ijk = 2,3,…,Nijkm, going along the y-direction (j = 2,3,…,Nj–1), the x-direction (i = 2,3,…,Ni–1), and the z-direction (k = 2,3,…,Nk–1), while the nodes are indexed by ijk = 1,2,…,Nijk. With this indexing, the single-index ijk for a cell and for its six-neighbors can be easily obtained from their position in the (x,y,z) space (see Table 4.5). Writing Eq. 4.52 or 4.68 for all cells, ijk = 2,3,…,Nijkm, produces a series of algebraic linear equations which can be presented in a matrix form as follows: A � � B (4.97) The matrix A contains the coefficients of the equations, a nb and a P , � is a column matrix of the dependent variable, and B is a column matrix of the source terms. The matrix A has diagonal blocks which are themselves tridiagonal, and sub- and super-diagonal blocks in which each block has two diagonals, thus it has only 7 non-zero diagonals while the other elements are zero. It is then not necessary to store all elements of the matrix A; only those seven diagonals need to be stored. To facilitate the storage, each non-zero diagonal is stored in a separate column matrix, i.e. A nb , nb = EWNSTB, and A P . Fig. 4.13 shows the form of the matrix A.
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FLOW AROUND A CYLINDER IN A SCOURED
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- iii - Flow around a Cylinder in a
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- v - Écoulement à Surface Libre
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- vii - Acknowledgements I wish to
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- ix - Table of Contents Abstract i
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- xi - 4.4 Pressure-velocity coupli
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Chapter 1 - 1.i - 1 Introduction 1.
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1 Introduction 1.1 Flow around a cy
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- 1.3 - pitot tubes. Ahmed and Raja
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Chapter 2 - 2.i - 2 Flow Measuremen
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2 Flow Measurements Abstract - 2.1
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2.1 Measurement design - 2.3 - The
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- 2.5 - The water circuit is a clos
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- 2.7 - Consider a target ―i‖ m
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- 2.9 - Obtaining the velocity comp
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- 2.11 - Fig. 2.4 Cartesian and cyl
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- 2.13 - transducer were used, a fo
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- 2.15 - typically needed for this
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- 2.17 - 2.3.3 Comparison to other
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- 2.19 - Fig. 2.7 Scour hole geomet
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- 2.21 - Fig. 2.8 Distributions of
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u ��u �� u� � Du exp�
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- 2.25 - �o , and accordingly the
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- 2.27 - Measurements in zone A. Th
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- 2.29 - and 0.3 u �� u ��
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- 2.31 - Fig. 2.12b Cont’d.
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- 2.33 - Fig. 2.12d Cont’d.
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2.5.4 Measurements in the plane �
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- 2.37 - Fig. 2.13b Cont’d.
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- 2.39 - Fig. 2.13d Cont’d.
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- 2.41 - the solid boundary of the
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- 2.43 - Fig. 2.14b Cont’d.
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- 2.45 - Fig. 2.14d Cont’d.
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- 2.47 - Turbulence intensities in
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- 2.49 - Fig. 2.15a Vertical distri
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- 2.51 - Fig. 2.15c Cont’d.
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- 2.53 - Reynolds stresses in the p
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- 2.55 - Fig. 2.16c Cont’d.
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2.6 Summary and conclusions - 2.57
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- 2.59 - Rolland, T. (1994). Develo
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Chapter 3 - 3.i - 3 Elaboration of
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- 3.1 - 3 Elaboration of the measur
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3.1 Introduction - 3.3 - Presented
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- 3.5 - Fig. 3.1 Measured velocity
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3.2.2 Flow pattern around the cylin
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- 3.9 - Fig. 3.2 Cont’d.
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Flow in the plane � = 45° and 90
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- 3.13 - Fig. 3.4 Contours of the m
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3.2.4 Vertical velocity (downward f
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- 3.17 - flow may undergo a rotatin
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- 3.19 - Fig. 3.7 Cont’d.
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- 3.21 - A similar observation, in
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- 3.23 - Fig. 3.9 Measured turbulen
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The following is to be observed: -
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- 3.27 - Fig. 3.10 Cont’d.
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- 3.29 - 3.4 Bed shear-stresses alo
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x [cm] - 3.31 - Table 3.1 Estimated
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- 3.33 - Fig. 3.12 Estimated bed sh
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- 3.35 - (see Fig. 3.10 and Fig. 3.
Page 119 and 120: - 3.37 - Fig. 3.14 Axonometric pres
Page 121 and 122: - 3.39 - U, U∞ [m/s] sectional av
Page 123 and 124: Chapter 4 - 4.i - 4 Numerical Model
Page 125 and 126: - 4.1 - 4 Numerical Model Developme
Page 127 and 128: �u �t �v �t �w �t �
Page 129 and 130: - 4.5 - The volume integrals of the
Page 131 and 132: - 4.7 - Fig. 4.1 Overall iterative
Page 133 and 134: - 4.9 - increase the computer stora
Page 135 and 136: - 4.11 - �� 1 ��
Page 137 and 138: - 4.13 - convective transport throu
Page 139 and 140: - 4.15 - n,��1 during a time st
Page 141 and 142: � for 0 � Pe e � q eL PE �
Page 143 and 144: 4.3.8 Source terms - 4.19 - The sou
Page 145 and 146: 2D � � � x �� b 2D �
Page 147 and 148: - 4.23 - b T � V P �t � n P
Page 149 and 150: - 4.25 - �� u ��1 � c i
Page 151 and 152: - 4.27 - Next, we need to define th
Page 153 and 154: 4.5 Boundary conditions 4.5.1 Bound
Page 155 and 156: - 4.31 - The above relation holds a
Page 157 and 158: - 4.33 - � extrapolate all variab
Page 159 and 160: G � � t 2 �V t - 4.35 - 2 �
Page 161 and 162: with � �� nt,b � ��
Page 163 and 164: - 4.39 - boundary node B are then a
Page 165 and 166: - 4.41 - Wall function for the �
Page 167 and 168: k and � equations - 4.43 - � se
Page 169: �� z-momentum: - 4.45 - ��1
Page 173 and 174: - 4.49 - Fig. 4.13 The structure of
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Page 177 and 178: 4.7 Summary - 4.53 - Development of
Page 179 and 180: - 4.55 - B, �B [-] constant and w
Page 181 and 182: - 4.57 - �, � 1 , � p [-] und
Page 183 and 184: Chapter 5 - 5.i - 5 Numerical Simul
Page 185 and 186: 5 Numerical Simulation Abstract - 5
Page 187 and 188: 5.2 Experimental data - 5.3 - 5.2.1
Page 189 and 190: - 5.5 - computational nodes. The ot
Page 191 and 192: - 5.7 - (i) Yulistiyanto data (ii)
Page 193 and 194: - 5.9 - ( p � � 1 [mm]), but th
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Page 199 and 200: - 5.15 - Fig. 5.6 Computational his
Page 201 and 202: - 5.17 - 5.5 Simulation of flow aro
Page 203 and 204: - 5.19 - Fig. 5.9 Definition sketch
Page 205 and 206: - 5.21 - Fig. 5.10 Computed (lines)
Page 207 and 208: - 5.23 - Fig. 5.11 Computed and mea
Page 209 and 210: - 5.25 - 1.2U ∞ of the measuremen
Page 211 and 212: Water-surface profile - 5.27 - The
Page 213 and 214: - 5.29 - using a Joukowski transfor
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Page 217 and 218: Velocity fields around the cylinder
Page 219 and 220: - 5.35 - Fig. 5.18 Computed and mea
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- 5.37 - than the measured one. The
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- 5.39 - Production and dissipation
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- 5.41 - Production of turbulent ki
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- 5.43 - If the above approach were
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- 5.45 - and surface profiles (see
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- 5.47 - Fig. 5.24 Surface boundary
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- 5.49 - S [m 2 ] surface area. So,
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Chapter 6 - 6.i - 6 Summary and Con
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- 6.1 - 6 Summary and Conclusions 6
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- 6.3 - The spatial distributions o
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- 6.5 - � Laboratory measurements
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- 6.7 - Fig. 6.1 Measured and compu
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IDENTITE - 7.1 - Curriculum Vitæ N
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- iii - Appendices Appendix A: Expe
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A Experimental Data - A.1 - The exp
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B Numerical Model B.1 Program struc
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- B.3 -
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B.2 Input data file - B.5 - The inp
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- B.7 - #31 imon1, jmon1, kmon1 thr
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BLO for blocked cells, INL for inle
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FLOW AROUND A CYLINDER - istiarto

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