Gas turbine engine blade

• US 6,554,572 B2
• Filed: 05/17/2001
• Issued: 04/29/2003
• Est. Priority Date: 05/17/2001
• Status: Expired due to Fees

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Singh, Hardev, Rinck, Gerard Anthony, Norton, Brian Alan, Stegemiller, Mark Edward
• Primary Examiner(s): Look, Edward K.
• Assistant Examiner(s): Kershteyn, Igor
• Application Number:
  US09/859,610
• Publication Number:
  US 20020187039A1
• Time in Patent Office: 712 Days
• Field of Search: 416/97.R, 416/96.R, 416/95, 415/115, 298/891, 298/897.21
• US Class Current: 416/97.00R
• CPC Class Codes: F01D 5/141 Shape, i.e. outer, aerodynamic form F01D5/148 - F01D5/20 take precedence; blade construction F01D5/147
• CPC Class Codes: F01D 5/147 Construction, i.e. structural features, e.g. of weight-saving hollow blades F01D5/148, F01D5/16 and F01D5/20 take precedence; blade shape F01D5/141; blades with cooling or heating channels or cavities F01D5/18; heating, heat-insulating or cooling means on blades F01D5/18
• CPC Class Codes: F01D 5/186 Film cooling F01D5/187 takes precedence
• CPC Class Codes: F01D 5/20 Specially-shaped blade tips to seal space between tips and stator F01D5/225 takes precedence
• CPC Class Codes: F05D 2240/80 Platforms for stationary or moving blades
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft
• CPC Class Codes: Y10T 29/49318 Repairing or disassembling
• CPC Class Codes: Y10T 29/49341 with cooling passage

Abstract

A turbine blade for a gas turbine engine. An existing blade was found to exhibit bowing, or a concave configuration facing the pressure side, along its trailing edge. The invention reduces bowing by (1) changing tilt, (2) changing lean, (3) reducing the number of cooling holes, while (4) changing the diameters of the cooling holes, to maintaining the total cooling flow unchanged.

Claims

1. A method of modifying a turbine blade in a gas turbine engine, comprising:

a) increasing tilt by 18.5 percent;

b) decreasing lean by 40 percent; and

c) reducing number of cooling holes, while increasing diameter of at least some holes, to maintain cooling airflow unchanged.

2. The method according to claim 1, further comprising the step of reducing temperature differential across the trailing edge to 68 percent of its previous value, under hot-day, full-power conditions.

3. The method according to claim 1, further comprising the step of reducing to 15 percent.

4. A system, comprising:

a) a gas turbine engine, which includes a first stage high-pressure turbine, in which turbine blades experience a temperature differential of T degrees F across their trailing edges; and

b) means for reducing the differential to 68 percent of T.

5. The system according to claim 4, wherein the gas turbine engine is of the CFE-50 type.

6. The system according to claim 4, wherein the means includes a tilt in the turbine blades of 3.2 degrees.

7. The system according to claim 4, wherein the means includes a lean of 2.1 degrees.

8. A method for reducing bow in a film-cooled turbine blade, which includes, on its pressure side, an arrangement of cooling holes which are defined into (A) a single row of tip cooling holes and (B) nine columns of holes, numbered beginning with a first column at a trailing edge, comprising the steps of:

providing in a first column (71);

9 holes total, 3 holes of diameter 16 mils and 6 holes of diameter 17 mils;

providing in a second column (72);

9 holes, of diameter 17 mils;

providing in a third column (73);

3 holes, of diameter 17 mils;

providing in a fourth column (74);

11 holes, of diameter 15 mils;

providing in a fifth column (75);

10 holes, of diameter 15 mils;

providing in a sixth column (76);

25 holes, staggered, of diameter 15 mils;

providing in a seventh column (77);

15 holes, of diameter 15 mils;

providing in a eighth column (78);

15 holes, of diameter 15 mils; and

providing in a ninth column (79);

21 holes, of diameter 13 mils.

9. The method according to claim 8, wherein the step of providing 25 holes, staggered, further comprises the step of arranging the 25 holes into two parallel columns.

10. The method according to claim 9, further comprising the step of providing vertical distances (AC, BD) between vertically adjacent holes, wherein the vertical distances in a column are equal.

11. The method according to claim 9, further comprising the step of providing stagger distances (AB, BC, CD) between holes, wherein the stagger distances are equal.

12. A method of modifying a turbine blade containing a row of holes near its tip and ten columns of holes, numbered from a trailing edge, comprising:

d) eliminating a sixth column;

e) replacing remaining columns with columns containing holes as follows;

i) replacing a first column by a column of 9 holes containing

A) 3 holes of 16 mil diameter, and

B) 6 holes of 17 mil diameter;

ii) replacing a second column by a column of 9 holes of 17 mils diameter;

iii) replacing a third column by a column of 3 holes of 17 mils diameter;

iv) replacing a fourth column by a column of 11 holes of 15 mils diameter;

v) replacing a fifth column by a column of 10 holes of 15 mils diameter;

vi) replacing a seventh column by a pair of columns containing 25 holes of 15 mils diameter;

vii) replacing an eighth column by a column of 15 holes of 15 mils diameter;

viii) replacing a ninth column by a column of 15 holes of 15 mils diameter;

ix) replacing a tenth column by a column of 21 holes of 13 mils diameter;

f) replacing the row of holes with a row of 8 holes of 12 mils diameter.

13. The method according to claim 12, and further comprising the step of changing blade tilt to 3.2 degrees.

14. The method according to claim 12, and further comprising the step of changing blade lean to 2.1 degrees.

15. A blade for a first stage of a high-pressure turbine in a gas-turbine engine, comprising:

a) a pressure side having

i) a row of 8 cooling holes near its tip, each hole of 12 mils diameter;

ii) nine columns of holes, as follows;

A) a first column (71) containing 9 holes total, 3 of diameter 16 mils and 6 of diameter 17 mils;

B) a second column (72) containing 9 holes of diameter 17 mils;

C) a third column (73) containing 3 holes of diameter 17 mils;

D) a fourth column (74) containing 11 holes of diameter 15 mils;

E) a fifth column (75) containing 10 holes of diameter 15 mils;

F) a sixth column (76) containing 25 holes, in two sub-columns, of diameter 15 mils;

G) a seventh column (77) containing 15 holes of diameter 15 mils;

H) an eighth column (78) containing 15 holes of diameter 15 mils; and

I) a ninth column (79) containing 21 holes of diameter 13 mils;

b) a lean of 2.1 degrees; and

c) a tilt of 3.2 degrees.