Tubrogrid - Error on cut-off at TE
 

Hi all. I generated a profile.curve file using matlab of a compressor blade, described by 12 sections. The profile chosen is NACA-65. If i use the original geometry of the naca-65, with null thickness at trailing edge, turbogrid gives no troubles and imports the geometry correctly. If i modify the naca-65 adding somewhat more thickness on TE (as it is obvious to do regarding a compressor blade profile), then, importing profile.curve in TurboGrid, i need to specify "Square or cut-off" at trailing edge. Doing this, the program returns error (it says that couldn't execute trimming at blade trail). I wonder what could be the problem but just can't find out. Thanks for helping.

Re: Tubrogrid - Error on cut-off at TE
 

Here is the errore message produced by the TurboGrid when i specify "cut-off or square" option for trailing edge:

"Trim operation failed to produce any surfaces for surface Blade_1_ex_trail"

Re: Tubrogrid - Error on cut-off at TE
 

Open profile.curve and write TE and TE2 next the two trailing edge points. Make it for every sections. When you import profile.curve in TG set TE cut-off! Regards

Re: Tubrogrid - Error on cut-off at TE
 

Thanks for helping but it makes no difference.

Re: Tubrogrid - Error on cut-off at TE
 

It's strange! Are you sure blade points are correct? How did you add the thikness? TG is very sensible and crashes if some points aren't written in series.

See this example about a cylindrical NACA 65 profile with cut off at 95 % of chord.

profile.curve in mm

# Section Hub

95 0.308 200 TE

90 0.812 200

85 1.387 200

80 1.989 200

75 2.586 200

70 3.158 200

65 3.684 200

60 4.148 200

55 4.532 200

50 4.814 200

45 4.965 200

40 4.998 200

35 4.926 200

30 4.762 200

25 4.505 200

20 4.145 200

15 3.668 200

10 3.042 200

7.5 2.649 200

5 2.179 200

2.5 1.576 200

1.25 1.171 200

0.75 0.934 200

0.5 0.774 200

0 0.000 200 LE

0.5 -0.77 200

0.75 -0.93 200

1.25 -1.167 200

2.5 -1.572 200

5 -2.175 200

7.5 -2.645 200

10 -3.038 200

15 -3.664 200

20 -4.141 200

25 -4.501 200

30 -4.758 200

35 -4.922 200

40 -4.994 200

45 -4.961 200

50 -4.81 200

55 -4.528 200

60 -4.144 200

65 -3.68 200

70 -3.154 200

75 -2.582 200

80 -1.985 200

85 -1.383 200

90 -0.808 200

95 -0.304 200 TE2

# Section Shroud

95 0.308 500 TE

90 0.812 500

85 1.387 500

80 1.989 500

75 2.586 500

70 3.158 500

65 3.684 500

60 4.148 500

55 4.532 500

50 4.814 500

45 4.965 500

40 4.998 500

35 4.926 500

30 4.762 500

25 4.505 500

20 4.145 500

15 3.668 500

10 3.042 500

7.5 2.649 500

5 2.179 500

2.5 1.576 500

1.25 1.171 500

0.75 0.934 500

0.5 0.774 500

0 0.000 500 LE

0.5 -0.77 500

0.75 -0.93 500

1.25 -1.167 500

2.5 -1.572 500

5 -2.175 500

7.5 -2.645 500

10 -3.038 500

15 -3.664 500

20 -4.141 500

25 -4.501 500

30 -4.758 500

35 -4.922 500

40 -4.994 500

45 -4.961 500

50 -4.81 500

55 -4.528 500

60 -4.144 500

65 -3.68 500

70 -3.154 500

75 -2.582 500

80 -1.985 500

85 -1.383 500

90 -0.808 500

95 -0.304 500 TE2

-------------------------------------------------------

hub.curve

-100 0 200

200 0 200

-------------------------------------------------------

shroud.curve

-100 0 500

200 0 500

-------------------------------------------------------

Regards

When I import blade profile without choosing cut-off, I got the same error message. The error disappears after I add more points into the profile. Maybe the points in my previous blade profile are too few.