**Tenth standard configuration (Modified cambered
NACA 0006 cascade at subsonic and transonic flow conditions)**

2D geomertry file: to be updated

Download data files:File Information

stcf10_1x.zip

(140 Kb)Time averaged blade surface pressure distributions

Aerodynamic lift coefficient and phase lead

Aerodynamic moment coefficient and phase lead

Time dependent blade surface MACH number

Time dependent blade surface pressure distribution: stcf10_2a.zip

(290 Kb)case 1-12 stcf10_2b.zip

(219 Kb)case 13-22 stcf10_2c.zip

(204 Kb)case 23-32

Time dependent blade surface pressure difference coef: stcf10_3a.zip

(195 Kb)case 1-12 stcf10_3b.zip

(162 Kb)case 13-22 stcf10_3c.zip

(168 Kb)case 23-32

The tenth Standard Configuration, included by proposal of Dr. J. M. Verdon at the United Technologies Research Center [1987a,c], is a two- dimensional compressor cascade of modified NACA 0006 profiles that operates at subsonic inlet and exit conditions. The geometry is given by Verdon [1987a] and is repeated here for convenience. The cascade has a stagger angle, g, of 45o and a gap/chord ratio, t, of unity. The blades are constructed by superimposing the thickness distribution of a modified NACA four digit series airfoil on a circular arc camber line. The thickness distribution is given by: (3.10.1) where HT is the nominal blade thickness. The coefficient of the x4 in eq. (3.10.1) differs from that used in the standard NACA airfoil definition (i.e., - 1.015) so that the example blades will close in as wedge-shaped trailing edges. The camber distribution is given by: (3.10.2) where HC (>0) is the height of the camber-line at midchord and is the radius of the circular arc camber line. The surface coordinates of the reference blade are therefore given by: (3.10.3) where the signs + and - refer to the upper (suction) and lower (pressure) surfaces, respectively, and q=tan-1(dC/dx). For the present example we set HT=0.06 and HC=0.05 to study the unsteady aerodynamic response of a vibrating cascade of cambered NACA 0006 airfoils. We consider two different steady-state inlet operating conditions. In the aeroelastic cases 1-16 the inlet Mach number, M1, and flow angle, b1, are 0.7 and - 55o, respectively; for cases 17-32, M1=0.8 and b1=- 58o (see Table 3.10.1). The flow through the cascade is assumed to satisfy a Kutta condition at blade trailing edges and, therefore, only inlet flow information must be specified. For M1=0.7 and b1=-55o, the mean or steady flow through the cascade is entirely subsonic; for M1=0.8 and b1=-58o it is transonic with a normal shock occurring in each blade passage. As aeroelastic test cases we consider single-degree- of-freedom blade heaving, normal to chord, and pitching motions at four different frequencies, k=0.25, 0.50, 0.75 and 1.0, and at interblade phase angles lying in the range -p_s_p. The amplitude of the heaving motion, h, is 0.01; that of the pitching motion, a, is 2o. The blade pitching axis lies at midchord, i.e. (xa,ya)=(0.5,0.05). We are interested in the following aerodynamic response information for each of the two inlet operating conditions given, at reduced frequencies of k=0.25, 0.50, 0.75 and 1.0 (see Table 3.10.1 for details): 1: The time-averaged blade surface pressure coefficient, and Mach number. 2: a: Amplitude, , and phase lead angle, , of the unsteady blade surface pressure coefficient for heaving and pitching motions at s=0o and s=90o. b: Amplitude, , and phase lead angle, , of the unsteady blade surface pressure difference coefficient for heaving and pitching motions at s=0o and s=90o. 3: a: The amplitude, , and phase lead angle, , of the unsteady lift coefficient per unit amplitude vs interblade phase angle for the heaving motions at -p_s_p. b: The amplitude, , and phase lead angle, , of the unsteady moment coefficient per unit amplitude vs interblade phase angle for the pitching motions at -p_s_p. 4: The aeroelastic damping coefficient, X, vs interblade phase angle for the heaving and pitching motions at -p_s_p. Usab and Verdon [1990, 1989b, 1987a,c], and Whitehead [1990] have already presented results on this cascade. Results from other prediction models were also recently presented [Huff, 1991; Hall, 1991]. Some very promising results have been obtained (these will be included in the complete updated report presently in preparation). When comparing these results with each other it must be considered that no analytical results exist. Only the mutual agreement between several similar theoretical methods can thus indicate the accuracy of the models. Stagger angle: g =45o Gap/chord: t =1.0 Pitch axis: (xa,ya) = (0.5,0.05)