Title

Contents.
  1. DREDMO (Dredge in Motions)
    1. Equilibrium Equations of Motion of a Ship
    2. Solution Method of Equilibrium Equations of Motion
    3. The t=0 problem
    4. Discontinuities
  2. The Two Dimensional Cutting Theory
    1. Description of The Process
    2. Literature Survey
    3. Determination of the Underpressure around the Blade
    4. Numerical Pore Pressure Calculations
    5. The Tip of the Blade Problem
    6. The Forces on the Blade
    7. Determination of the Shear Angle b
    8. The Coefficients a1 and a2
    9. Determination of the Coefficients c1, c2, d1 and d2
    10. Determination of f and d from Cutting Tests
    11. The Effect of a Transversal Velocity Component
    12. Wear and Side Effects
    13. Specific Cutting Energy
    14. Tables
      1. Dimensionless Pore Pressures (2.01)
      2. The Non-Cavitating Cutting Process, b, c1, c2, a1 for hb/hi=1 (2.02, 2.14, 2.20 & 2.08, without underpressure behind the blade)
      3. The Non-Cavitating Cutting Process, b, c1, c2, a1 for hb/hi=2 (2.03, 2.15, 2.21, & 2.09, without underpressure behind the blade)
      4. The Non-Cavitating Cutting Process, b, c1, c2, a1 for hb/hi=3 (2.04, 2.16, 2.22, & 2.10, without underpressure behind the blade)
      5. The Cavitating Cutting Process, b, d1, d2 for hb/hi=1 (2.05, 2.26 & 2.32, without underpressure behind the blade)
      6. The Cavitating Cutting Process, b, d1, d2 for hb/hi=2 (2.06, 2.27 & 2.33, without underpressure behind the blade)
      7. The Cavitating Cutting Process, b, d1, d2 for hb/hi=3 (2.07, 2.28 & 2.34, without underpressure behind the blade)
      8. The Non-Cavitating Cutting Process, b, c1, c2, a1 for hb/hi=1 (2.02, 2.17, 2.23 & 2.11, with underpressure behind the blade)
      9. The Non-Cavitating Cutting Process, b, c1, c2, a1 for hb/hi=2 (2.03, 2.18, 2.24, & 2.12, with underpressure behind the blade)
      10. The Non-Cavitating Cutting Process, b, c1, c2, a1 for hb/hi=3 (2.04, 2.19, 2.25, & 2.13, with underpressure behind the blade)
      11. The Cavitating Cutting Process, b, d1, d2 for hb/hi=1 (2.05, 2.29 & 2.35, with underpressure behind the blade)
      12. The Cavitating Cutting Process, b, d1, d2 for hb/hi=2 (2.06, 2.30 & 2.36, with underpressure behind the blade)
      13. The Cavitating Cutting Process, b, d1, d2 for hb/hi=3 (2.07, 2.31 & 2.37, with underpressure behind the blade)
  3. Verification of the Cutting Theory
    1. Description of the Test Stand
    2. Testing Program
    3. Water Resistance
    4. The Influence of the Width of the Blade
    5. Side Effects
    6. Scaling Effects
    7. Comparison of Measurements versus Theory
    8. Location of the Resulting Cutting Force
    9. Verification of Forces & Pore Pressures in a 200 mm Sand
    10. Verification of Forces & Pore Pressures in a 105 mm Sand
    11. Determination of f and d from Measurements
    12. General Conclusions
  4. Analytical Model of the Forces on a Cutterhead
    1. Introduction
    2. Simplifications and Basic Equations
    3. Transformation of the Forces to the Cutterhead Related Axis System
    4. Integration of Momentary Cutting Forces and Cutting Torque
    5. The Derived Quantities
    6. Simplification of the Equations
    7. Specific Cutting Energy
    8. Tables
      1. Table 4.01: The coefficients f1, f2 and f5 as a function of the angle W1.
      2. Table 4.02: The coefficients f3, f4 and f6 as a function of W0 and W1.
      3. Table 4.03: The coefficients f3, f4 and f6 as a function of W0 and W1.
      4. Table 4.04: The coefficients f3, f4 and f6 as a function of W0 and W1.
      5. Table 4.05: The coefficients f3, f4 and f6 as a function of W0 and W1.
  5. Analytical Model of the Forces on a Dredging Wheel
    1. Introduction
    2. The Non-Cavitating Cutting Process
    3. The Cavitating Cutting Process
    4. Simplification of the Equations
    5. Specific Cutting Energy
    6. The Partly Cavitating Cutting Process
    7. Correction for the Direction of the Forces
    8. The Alternative Bank Cut
    9. Tables
      1. Table 5.01: Coefficients fxgc, fygc, fzgc and mgc at S=0.1R, W2=-3, non-cavitating
      2. Table 5.02: Coefficients fxgc, fygc, fzgc and mgc at S=0.2R, W2=-6, non-cavitating
      3. Table 5.03: Coefficients fxgc, fygc, fzgc and mgc at S=0.3R, W2=-9, non-cavitating
      4. Table 5.04: Coefficients fxgc, fygc, fzgc and mgc at S=0.4R, W2=-11, non-cavitating
      5. Table 5.05: Coefficients fxgc, fygc, fzgc and mgc at S=0.5R, W2=-14, non-cavitating
      6. Table 5.06: Coefficients fxca, fyca, fzca and mca at S=0.1R, W2=-3, cavitating
      7. Table 5.07: Coefficients fxca, fyca, fzca and mca at S=0.2R, W2=-6, cavitating
      8. Table 5.08: Coefficients fxca, fyca, fzca and mca at S=0.3R, W2=-9, cavitating
      9. Table 5.09: Coefficients fxca, fyca, fzca and mca at S=0.4R, W2=-11, cavitating
      10. Table 5.10: Coefficients fxca, fyca, fzca and mca at S=0.5R, W2=-14, cavitating
  6. Scale Rules
    1. Scale Rules
  7. Verification of the Analytical Models for Cutterhead and Dredging Wheel
    1. Introduction
    2. Test Stand Cutterhead Experiments
    3. Forces and Torque on the Cutterhead
    4. Test Stand Dredging Wheel Experiments
    5. Mechanical and Hydraulical Losses
    6. Driving Torque
    7. Conclusions
    8. Figures Cutterhead Tests
    9. Figures Dredging Wheel Tests
  8. Numerical Model of the Forces on a Rotating Excavating Element (Cutterhead or Dredging Wheel)
    1. Introduction
    2. Definitions
    3. Transformations
    4. Velocity Vectors
    5. Layer Thickness, Blade Angle and Blade Height
    6. Forces in Densily Packed and Water Saturated Sand
    7. Transformation to the Fixed Axis System
  9. Comparison of the Numerical Force Model versus the Analytical Models
    1. Introduction
    2. Numerical Calculations of the Forces on a Disc Bottom Cutterhead
    3. Conclusions
    4. Figures Disc Bottom Cutterhead Tests
  10. The Three Dimensional Moving Cutterhead
    1. Introduction
    2. Determination of the Shape and the Dimensions of the Bank
    3. The Influence of Radial Velocity Variations on the Loads on the Cutterhead
    4. The Influence of Axial Velocity Variations on the Loads on the Cutterhead
    5. Specific Energy and Conclusions
  11. Verification of the Loads on a Three Dimensional Moving Cutterhead
    1. Description of the Test Stand
    2. The Test Program
    3. The Signals Measured
    4. Signal Processing
    5. Macroscopic Cutting Behavior
    6. Parameters of Influence
    7. Conclusions Macroscopic Behavior
    8. Verification Radial Velocity Variations
    9. Verification Axial Velocity Variations
    10. Conclusions
  12. Conclusions
    1. Verification Two-Dimensional Cutting Theory
    2. Verification Cutterhead and Dredging Wheel
    3. Verification Three-Dimensional Moving Cutterhead
    4. Possible Further Research
  13. Bibliography
    1. Bibliography
  14. List of Symbols Used.
    1. General List of Symbols Used
    2. List of Symbols Used in Chapter 1
    3. List of Symbols Used in Chapter 8
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This is a translation of the dissertation of Dr.ir. S.A. Miedema, dated September 15th 1987 .
The dissertation was originally published in Dutch by the:
Delft University of Technology
Faculty of Mechanical Engineering and Marine Technology
Chair of Dredging Technology
Mekelweg 2
2628 CD, Delft   
The Netherlands

It is advised to also read the papers following this dissertation, since the theory developed has been refined and extended.

Visit our new site at: dredgingengineering.com

Last modified Saturday April 27, 2002 by: Sape A. Miedema

Translation by: Laurens de Jonge

Figures, equations and tables by: Erik Miedema

Copyright April, 2002 Dr.ir. S.A. Miedema


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