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The Delft Sand, Clay & Rock Cutting Model, 2019a

The Delft Sand, Clay & Rock Cutting Model, 2019a

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<strong>The</strong> <strong>Delft</strong> <strong>Sand</strong>, <strong>Clay</strong> & <strong>Rock</strong> <strong>Cutting</strong> <strong>Model</strong>.<br />

Teta2 = Alpha + Beta<br />

Teta3 = Pi - Beta<br />

Teta4 = Pi + Beta<br />

Lmax = Hi / Sin(Beta)<br />

L1 = Hb / Sin(Alpha)<br />

L4 = 0.9 * Hi *(Hi/Hb)^0.5*(1.85*Alpha)^2*(Ki/Kmax)^0.4<br />

N = 100<br />

StepL = Lmax / N<br />

P = 0<br />

DPMax = RhoW * G * (Z + 10)<br />

For I = 0 To N<br />

L = I * StepL + 0.0000000001<br />

‘Determine the 4 lengths<br />

S1 = (Lmax - L) * (Pi/2+Teta1) + L1<br />

S2 = 0.8*L * Teta2<br />

S3 = 0.8*L * Teta3<br />

S4 = (Lmax - L) * Teta4 + L4<br />

‘Determine the 4 resistances<br />

R1 = S1 / Kmax<br />

R2 = S2 / Kmax<br />

R3 = S3 / Ki<br />

R4 = S4 / Ki<br />

‘Determine the total resistance<br />

Rt = 1 / (1 / R1 + 1 / R2 + 1 / R3 + 1 / R4)<br />

‘Determine the pore vacuum pressure in point I<br />

DP = RhoW * G * Vc * E * Sin(Beta) * Rt<br />

‘Integrate the pore vacuum pressure<br />

P = P + DP<br />

‘Store the pore vacuum pressure in point I<br />

P1(I)=DP<br />

Next I<br />

‘Store the pore vacuum pressure at the tip of the blade<br />

Ptip=DP<br />

‘Determine the average pore vacuum pressure with correction for integration<br />

P1m = (P - Ptip / 2) / N<br />

‘Determine the pore vacuum pressure on the blade<br />

‘Determine the 2 lengths<br />

S1=L1<br />

S2=0.8*Lmax*Teta2<br />

‘Determine the 2 resistances<br />

R1=S1/Kmax<br />

R2=S2/Kmax<br />

‘Compensate R2 for the number of intervals and the geometry<br />

R2=R2*N*1.75*(Hi*Sin(Alpha)/(Hb*Sin(Beta))<br />

‘Determine the effective resistance<br />

Rt=1/(1/R1+1/R2)<br />

‘Determine the total flow over the blade at the tip of the blade<br />

Q=Ptip/(RhoW*G*Rt)<br />

‘Determine the two flows, Q1 over the blade and Q2 from entrainment<br />

Q1=Ptip/(Rhow*G*R1)<br />

Q2=Ptip/(Rhow*G*R2)<br />

‘Determine the pressure effect near the tip of the blade<br />

TipEffect=Int(0.05*N*Alpha)<br />

‘Now determine the pore vacuum pressure distribution on the blade<br />

P=0<br />

For I = 1 To N<br />

‘Determine the length of the top of the blade to point I<br />

Page 142 of 454 TOC Copyright © Dr.ir. S.A. Miedema

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