Experimental data for friction coefficient along the bottom wall 
at 0 and 6 degree flap angle from Driver & Seegmiller (1985).

# 0 degree flap angle 
x/S [-],  Cf [-],  +-dCf/Cf [-]
0.000,   0.00000,  0.00
0.484,   0.00009,  0.15
1.804,  -0.00011,  0.17
2.804,  -0.00052,  0.21
3.804,  -0.00102,  0.16
4.804,  -0.00082,  0.15
5.882,  -0.00022,  0.28
7.090,   0.00045,  0.37
7.978,   0.00102,  0.12
9.196,   0.00118,  0.09
11.196,  0.00154,  0.08
13.196,  0.00173,  0.07
16.196,  0.00191,  0.07
20.196,  0.00202,  0.07
24.136,  0.00204,  0.07
28.130,  0.00205,  0.10
32.196,  0.00212,  0.07
35.994,  0.00230,  0.08

# 6 degree flap angle
x/S [-],  Cf [-],  +-dCf/Cf [-]
0.000,   0.00000,  0.00
0.238,   0.00014,  0.07
1.790,  -0.00011,  0.10
2.804,  -0.00033,  0.16
3.804,  -0.00066,  0.13
4.804,  -0.00079,  0.14
5.804,  -0.00058,  0.10
6.804,  -0.00037,  0.30
7.804,  -0.00008,  0.37
9.876,   0.00031,  0.17
11.196,  0.00047,  0.13
12.196,  0.00059,  0.12
14.196,  0.00066,  0.10
16.198,  0.00073,  0.07
20.196,  0.00077,  0.06
28.106,  0.00077,  0.06
36.196,  0.00079,  0.08