Boundary Layer with Adverse Pressure Gradient
Experiments by Gasser and Thomann
Description
Two-dimensional incompressible turbulent boundary layers with strong adverse pressure gradients.
Fig. 1: Flow geometry and test section
The boundary layer develops over the inner wall of an annular pipe of diameter 200 mm. As shown in figure 1, the streamwise pressure gradient is generated by suction of air through a perforated section of the concentric inner tube of the annulus. This inner tube is of diameter 80 mm, and can be moved in the axial direction, so that its distance from the measurement section at \(x_M\) can be varied. \(x_A\) denotes the distance of this porous section upstream of the measurement location (negative values for \(x_A\) indicate cases where the porous section was located downstream of \(x_M\)).
The measurement location \(x_M\) is 675 mm downstream of the straight pipe inlet. Measurements of the boundary layer are also provided at \(x_E\) (400 mm upstream of \(x_M\)), and these could be used as inlet conditions for most cases.
Results are reported for two different suction conditions (AG1 and AG2) and for different values of the dynamic pressure \(q_D=P_o - P_D\), as listed in the table below. In each case, a number of positions of the perforated section, \(x_A\), are considered.
| \(q_D\) [Pa] | ||
| AG1 | 1000 | - |
| AG2 | 1000 | 600 |
Measurement Techniques
Velocity measured using Pitot tube.
Velocity and turbulence statistics measured with hot wire.
Available Measurements
Data available include:
- Wall pressure and shear stress measurements
- Mean velocity profiles across and along the pipe for various \(x_A\) locations
Sample plots of selected quantities are available.
The files can be downloaded individually, or compressed archives of all data files may be downloaded in the formats:
Boundary layer measurements at Section \(x_E\) (for both \(q_D=600\) and \(1000\) Pa cases)
| File | Description |
|---|---|
| e_hw.dat | Hot-wire mean velocity and Reynolds stress profiles |
| e_pi.dat | Pitot tube mean velocity profiles |
| e_tauw.dat | Circumferential distribution of wall shear stress |
Measurements at Section \(x_M\)
| Hot-wire mean velocity and Reynolds stress profiles | |
|---|---|
| m_hw_1.dat | Case AG1/1000, for \(x_A=-100\), \(0\), \(50\), \(100\), \(200\), \(300\) mm |
| m_hw_2.dat | Case AG2/1000, for \(x_A=-100\), \(0\), \(50\), \(100\), \(200\), \(300\) mm |
| m_hw_3.dat | Case AG2/600, for \(x_A=-100\), \(50\), \(100\), \(300\) mm |
| Pitot tube mean velocity profiles | |
| m_pi_1.dat | Case AG1/1000, for \(x_A=-100\), \(0\), \(50\), \(100\), \(200\), \(300\) mm |
| m_pi_2.dat | Case AG2/1000, for \(x_A=-100\), \(0\), \(50\), \(100\), \(200\), \(300\) mm |
| m_pi_3.dat | Case AG2/600, for \(x_A=-100\), \(50\), \(100\), \(300\) mm |
| Wall shear stress measurements | |
| m_tauw.dat | Measurements for all three cases, with \(x_A\) ranging from \(-100\) to \(400\) mm |
| m_tauw_p.dat | Measurements with wall pulsed-wire for case AG2/600, for \(x_A\) ranging from \(20\) to \(400\) mm |
Pressure measurements along the pipe
| Pressure distribution along the pipe wall, from \(x=230\) to \(715\) mm | |
|---|---|
| r_pres_1.dat | Case AG1/1000, for \(x_A\) ranging from \(-100\) to \(400\) mm |
| r_pres_2.dat | Case AG2/1000, for \(x_A\) ranging from \(-100\) to \(400\) mm |
| r_pres_3.dat | Case AG2/600, for \(x_A\) ranging from \(-100\) to \(400\) mm |
Velocity measurements along the pipe
| Mean velocity distribution along selected sections of the pipe | |
|---|---|
| r_v_30_1.dat | Case AG1/1000, at \(y=30\) mm, for \(x_A\) ranging from \(-75\) to \(300\) mm |
| r_v_30_2.dat | Case AG2/1000, at \(y=30\) mm, for \(x_A\) ranging from \(-75\) to \(300\) mm |
| r_v_40_1.dat | Case AG1/1000, at \(y=40\) mm, for \(x_A\) ranging from \(-75\) to \(300\) mm |
| r_v_40_2.dat | Case AG2/1000, at \(y=40\) mm, for \(x_A\) ranging from \(-75\) to \(300\) mm |
| r_v_40_3.dat | Case AG2/600, at \(y=40\) mm, for \(x_A\) ranging from \(-75\) to \(300\) mm |
References
- Gasser, D. (1992). Experimentelle Untersuchung stark verzoegerter turbulenter Grenzschichten. PhD Thesis, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland.
- Hirt, F., Thomann, H. (1986). Measurement of wall shear stress in turbulent boundary layers subject to strong pressure gradients. J. Fluid Mech., Vol. 171, pp. 547-562.
Indexed data:
| case019 (dbcase, semi_confined_flow) | |
|---|---|
| case | 019 |
| title | Boundary Layer with Adverse Pressure Gradient |
| author | Gasser, Thomann |
| year | 1992 |
| type | EXP |
| flow_tag | axisymmetric, 2dbl |