1. A method of polymerization comprising:
(a) supplying a monomer having one or more of the following structures:
wherein R1 and R2 are selected from a hydrogen atom or an alkyl group or an aromatic group, or a cyclic alkyl group or a polyether, and combinations thereof and R3 is selected from an alkyl group, aromatic functionality, heteroaromatic functionality, cyclic alkyl group, heterocyclic group, or combinations thereof, wherein at least 50 mole % of R1 and R2 are a hydrogen atom to provide carboxylic acid functionality;
(b) combining at least one of monomers (I), (II) andor (III) with a solvent and partially neutralizing the carboxylic acid functionality at a level of 25.0 mole % to 85.0 mole % for each mole of carboxylic acid functionality present to provide a monomersolvent polymerizing media having an exposed surface area (SAPM) and a density (DPM);
(c) polymerizing said monomers in a reactor to provide an exothermic heat of polymerization (\u0394Hp) and allowing said solvent to evaporate from said reactor to provide an endothermic heat of vaporization (\u0394Hv) wherein \u0394Hp and \u0394Hv maintain the temperature of said polymerization at 50.0\xb0 C. to 150\xb0 C.;
(d) removing said polymerized monomers from said reactor and increasing the SAPM and decreasing DPM and maintaining the temperature of said polymerization at 50.0\xb0 C. to 150\xb0 C.
2. The method of claim 1 wherein following (d) the value of DPM increases to maintain the temperature of polymerization at or above 50.0\xb0 C.
3. The method of claim 1 wherein said polymerizing of said monomers in step (c) occurs over a period of 3.0 minutes to 60.0 minutes.
4. The method of claim 1 wherein said solvent is allowed to evaporate over a period of 1.0 minute to 15.0 minutes.
5. The method of claim 1 wherein in step (c) the value of DPM decreases.
6. The method of claim 1 wherein in step (c) the value of SAPM is increased 10% to 500%.
7. The method of claim 1 wherein in step (d) the polymerization media has an exposed surface area of 0.03 m2kilogram of polymerization media to 1.0 m2kilogram of polymerization media.
8. The method of claim 1 wherein the percent conversion is 50% to 99.9%.
9. The method of claim 1 wherein said monomers are present in said solvent at a percent solids content of 50 wt. % to 90 wt. %.
10. The method of claim 1 wherein said neutralization of said carboxylic acid functionality is 40 mole % to 60 mole % for each mole of carboxylic acid.
11. The method of claim 1 wherein said neutralization of said carboxylic acid functionality is 45 mole % to 55 mole % for each mole of carboxylic acid.
12. The method of claim 1 wherein said polymerization provides a polymer with a weight average molecular weight (Mw) of at or above 20,000 gmole.
13. The method of claim 1 wherein said polymerization provides a polymer with a weight average molecular weight (Mw) of 20,000 to 1,000,000 gmole.
14. The method of claim 1 wherein said polymerization provides a polymer which indicates 13C NMR triads having a syndiotacticity of greater than 58.0%.
15. The method of claim 1 wherein said partial neutralization takes place over a time period not to exceed 2.0 hours.
16. The method of claim 1 wherein said partial neutralization takes place over a time period not to exceed 1.0 hour.
17. The method of claim 1 wherein said polymerization is initiated by a free radical initiator wherein said initiator is present at a level of 0.05 wt. % to 15.0 wt. %.
18. The method of claim 1 wherein said polymerization is initiated by a free radical initiator wherein said initiator is present at a level of 0.1 wt. % to 6.0 wt. %.
19. The method of claim 1 wherein said polymerization is initiated by a free radical initiator wherein said initiator is present at a level of 0.20 wt. % to 4.0 wt. %.
20. The method of claim 1 wherein said monomer is itaconic acid.
21. The method of claim 1 wherein said monomers are capable of isomerization to non-polymerizing monomers, wherein the level of non-polymerizing monomer is maintained at a level of less than or equal to 20.0 mole percent for each mole of acidic monomer present.
22. The method of claim 1 wherein said polymerization is run continuously.
23. A method of polymerization comprising:
(a) supplying a monomer having the following structure:
wherein R1 and R2 are selected from a hydrogen atom or an alkyl group or an aromatic group, or a cyclic alkyl group or a polyether, and combinations thereof and R3 is selected from an alkyl group, aromatic functionality, heteroaromatic functionality, cyclic alkyl group, heterocyclic group, or combinations thereof, wherein at least 50 mole % of R1 and R2 are a hydrogen atom to provide carboxylic acid functionality;
(b) combining said monomer with a solvent and partially neutralizing the carboxylic acid functionality at a level of 25.0 mole % to 85.0 mole % for each mole of carboxylic acid functionality present to provide a monomersolvent polymerizing media having an exposed surface area (SAPM) and a density (DPM);
(c) polymerizing said monomer in a reactor to provide an exothermic heat of polymerization (\u0394Hp) and allowing said solvent to evaporate from said reactor to provide an endothermic heat of vaporization (\u0394Hv) wherein \u0394Hp and \u0394Hv maintain the temperature of said polymerization at 50.0\xb0 C. to 150\xb0 C.;
(d) removing said polymerized monomers from said reactor and increasing the SAPM and decreasing DPM and maintaining the temperature of said polymerization at 50.0\xb0 C. to 150\xb0 C.
24. The method of claim 23 wherein following (d) the value of DPM is allowed to increase to maintain the temperature of polymerization at or above 50.0\xb0 C.
25. The method of claim 23 wherein said polymerizing of said monomer in step (c) occurs over a period of 3.0 minutes to 60.0 minutes.
26. The method of claim 23 wherein said solvent is allowed to evaporate over a period of 1.0 minute to 15.0 minutes.
27. The method of claim 23 wherein in step (c) the value of DPM decreases.
28. The method of claim 23 wherein in step (d) the polymerization media has an exposed surface area of 0.03 m2kilogram of polymerization media to 1.0 m2kilogram of polymerization media.
29. The method of claim 23 wherein the percent conversion is 50% to 99.9%.
30. The method of claim 23 wherein said monomers are present in said solvent at a percent solids content of 50 wt. % to 90 wt. %.
31. The method of claim 23 wherein said neutralization of said carboxylic acid functionality is 40 mole % to 60 mole % for each mole of carboxylic acid.
32. The method of claim 23 wherein said neutralization of said carboxylic acid functionality is 45 mole % to 55 mole % for each mole of carboxylic acid.
33. The method of claim 23 wherein said polymerization provides a polymer with a weight average molecular weight (Mw) of at or above 20,000 gmole.
34. The method of claim 23 wherein said polymerization provides a polymer with a weight average molecular weight (Mw) of 20,000 to 1,000,000 gmole.
35. The method of claim 23 wherein said polymerization provides a polymer which indicates 13C NMR triads having a syndiotacticity of greater than 58.0%.
36. The method of claim 23 wherein said partial neutralization takes place over a time period not to exceed 2.0 hours.
37. The method of claim 23 wherein said partial neutralization takes place over a time period not to exceed 1.0 hour.
38. The method of claim 23 wherein said polymerization is initiated by a free radical initiator wherein said initiator is present at a level of 0.05 wt. % to 15.0 wt. %.
39. The method of claim 23 wherein said polymerization is initiated by a free radical initiator wherein said initiator is present at a level of 0.1 wt. % to 6.0 wt. %.
40. The method of claim 23 wherein said polymerization is initiated by a free radical initiator wherein said initiator is present at a level of 0.20 wt. % to 4.0 wt. %.
41. The method of claim 23 wherein said monomer is itaconic acid.
42. The method of claim 23 wherein said monomers are capable of isomerization to non-polymerizing monomers, wherein the level of non-polymerizing monomer is maintained at a level of less than or equal to 20.0 mole percent for each mole of acidic monomer present.
43. The method of claim 23 wherein said polymerization is run continuously.
44. A method of polymerization comprising:
(a) supplying a monomer having one or more of the following structures:
wherein R1 and R2 are selected from a hydrogen atom or an alkyl group or an aromatic group, or a cyclic alkyl group or a polyether, and combinations thereof and R3 is selected from an alkyl group, aromatic functionality, heteroaromatic functionality, cyclic alkyl group, heterocyclic group, or combinations thereof, wherein at least 50 mole % of R1 and R2 are a hydrogen atom to provide carboxylic acid functionality;
(b) combining at least one of monomers (I), (II) andor (III) with a solvent and partially neutralizing the carboxylic acid functionality at a level of 25.0 mole % to 85.0 mole % for each mole of carboxylic acid functionality present to provide a monomersolvent polymerizing media having an exposed surface area (SAPM) and a density (DPM);
(c) polymerizing said monomers in a reactor to provide an exothermic heat of polymerization (\u0394Hp) and allowing said solvent to evaporate from said reactor to provide an endothermic heat of vaporization (\u0394Hv) wherein \u0394Hp and \u0394Hv maintain the temperature of said polymerization at 50.0\xb0 C. to 150\xb0 C.;
(d) removing said polymerized monomers from said reactor and increasing the SAPM and decreasing DPM and maintaining the temperature of said polymerization at 50.0\xb0 C. to 150\xb0 C.;
wherein the percent conversion of monomer to polymer is 50% to 99.9% with: (1) a weight average molecular weight at or above 20,000 gmole; andor (2) 13C NMR triad syndiotacticity greater than 58.0%.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A compressor for a gas turbine engine, the compressor comprising:
an annular inlet duct having an annular hub side wall and an annular shroud side wall extending around the hub side wall spaced apart therefrom;
at least one rotor having an array of blades mounted on a rotatable shaft, the blades extending across a flow path in fluid communication and in alignment with the inlet duct; and
a plurality of circumferentially spaced apart inlet guide vanes extending across the inlet duct from the hub side wall to the shroud side wall, each vane being pivotable about a pivot axis thereof, each vane defining an airfoil portion with opposed leading and trailing edges, the airfoil portion being twisted such that at each location of the airfoil portion along the pivot axis, an angle is defined between a respective chord extending between the leading and trailing edges and a same reference plane containing the pivot axis and extending radially with respect to the compressor, the angle varying from a minimum value near the hub side wall to a maximum value near the shroud side wall, the angle being measured along a direction of rotation of the rotor.
2. The compressor as defined in claim 1, wherein the inlet duct has an upstream portion extending substantially radially with respect to the compressor and a downstream portion extending substantially axially with respect to the compressor, the pivot axis of each vane extending substantially axially.
3. The compressor as defined in claim 1, wherein the angle varies non-linearly along the pivot axis as a function of a distance from the hub side wall.
4. The compressor as defined in claim 1, wherein a relationship between the angle and a distance from the hub side wall is defined by a parabolic curve.
5. The compressor as defined in claim 2, wherein the twist angle at a given distance from the hub side wall corresponds approximately to \u03b11 as defined by
tan
\u2061
(
\u03b1
1
)
=
r
2
r
1
\u2062
C
m
\u2062
\u2062
2
C
m
\u2062
\u2062
1
\u2062
tan
\u2061
(
\u03b1
2
)
,
where \u03b12 is an angle of flow at the leading edge of a blade of the rotor at a corresponding distance from the hub side wall, r1 is a radial distance between the trailing edge of the vane and a rotational axis of the compressor at the given distance from the hub side wall, r2 is a radial distance between the leading edge of the blade and the rotational axis of the compressor at the corresponding distance from the hub side wall, Cm1 is a meridional velocity of the flow adjacent the trailing edge of the vane at the given distance from the hub side wall, and Cm2 is a meridional velocity of the flow adjacent the leading edge of blade at the corresponding distance from the hub side wall, with the given distance from the hub side wall and the corresponding distance from the hub side wall corresponding to a same fraction of a span of the vane and blade, respectively.
6. The compressor as defined in claim 1, wherein a variation of the angle from the hub side wall to a mid-point between the hub and shroud side walls is greater than a variation of the angle from the mid-point to the shroud side wall.
7. The compressor as defined in claim 1, wherein the each vane pivots from a first substantially radial position to a second position, and with the vane in the first position, the angle has a negative value near the hub side wall and a positive value near the shroud side wall.
8. The compressor as defined in claim 1, wherein the angle continuously varies in a same direction from the hub end to the tip end.
9. An inlet guide vane for a compressor of a gas turbine engine, the vane comprising:
a hub end configured to be received in a hub side of a gas path;
a tip end configured to be received in an opposed side of the gas path, the hub and tip ends being aligned and defining an axis of the vane extending therethrough; and
an airfoil portion extending between the hub end and the tip end, the airfoil portion defining opposed leading and trailing edges, the airfoil portion being twisted such that at each location of the airfoil portion along the axis, an angle is defined between a respective chord extending between the leading and trailing edges and a same reference plane containing the axis, the angle varying non-linearly along the axis as a function of a distance from the hub end.
10. The guide vane as defined in claim 9, wherein a relationship between the angle and the distance from the hub end is defined by a parabolic curve.
11. The guide vane as defined in claim 9, wherein a variation of the angle from the hub end to a mid-point between the hub and tip ends is greater than a variation of the angle from the mid-point to the tip end.
12. The guide vane as defined in claim 9, wherein the angle continuously varies in a same direction from the hub end to the tip end.
13. A method of reducing vortex whistle in a radial inlet of a compressor having a shroud side wall surrounding a hub side wall thereof, the method comprising swirling a flow along a trailing edge of each one of a plurality of axial inlet guide vanes extending between the hub side and shroud side walls, wherein swirling the flow along the trailing edge includes generating a swirl having a first angle adjacent the hub side wall and generating a swirl having a second angle larger than the first angle adjacent the shroud side wall.
14. The method according to claim 13, wherein swirling the flow along the trailing edge further includes generating a swirl between the hub side and shroud side walls having an angle varying non-linearly between the first angle and the second angle as a function of a distance from the hub side wall.
15. The method according to claim 14, wherein the swirl is generated such that a variation of the angle from the hub side wall to a mid-point between the hub and shroud side walls is greater than a variation of the angle from the mid-point to the shroud side wall.
16. The method according to claim 13, wherein swirling the flow along the trailing edge further includes generating a swirl between the hub side and shroud side walls having a swirl angle varying between the first angle and the second angle, a relationship between the swirl angle and a distance from the hub side wall being defined by a parabolic curve.
17. The method according to claim 13, further comprising selecting a distribution of a swirl angle along the trailing edge of each one of the vanes to produce a swirl along a leading edge of each blade of a rotor of the compressor having an angle varying linearly as a function of a distance from the hub side wall, the distribution of the swirl angle along the trailing edge of each one of the vanes including the first and second angles.
18. The method according to claim 13, further comprising selecting a distribution of a swirl angle along the trailing edge of each one of the vanes to produce a swirl along a leading edge of each blade of a rotor of the compressor selected based on a performance of the compressor at idle, the distribution of the swirl angle along the trailing edge of each one of the vanes including the first and second angles.
19. The method according to claim 13, further comprising selecting a distribution of a swirl angle along the trailing edge of each one of the vanes to produce a desired distribution of an angle of flow along a leading edge of each blade of a first rotor of the compressor, the distribution of the swirl angle along the trailing edge of each one of the vanes including the first and second angles and being determined according to
tan
\u2061
(
\u03b1
1
)
=
r
2
r
1
\u2062
C
m
\u2062
\u2062
2
C
m
\u2062
\u2062
1
\u2062
tan
\u2061
(
\u03b1
2
)
,
where \u03b11 is the swirl angle at the trailing edge of the vane at a given fraction of a span thereof, \u03b12 is the angle of flow at the leading edge of the blade at the given fraction of a span thereof, r1 is a radial distance between the trailing edge of the vane and a rotational axis of the compressor at the given fraction of the span of the vane, r2 is a radial distance between the leading edge of the blade and the rotational axis of the compressor at the given fraction of the span of the blade. Cm1 is a meridional flow velocity adjacent the trailing edge of the vane at the given fraction of the span thereof, and Cm2 is a meridional flow velocity adjacent the leading edge of the blade at the given fraction of the span thereof.
20. A method of selecting a twist angle of an inlet guide vane for a compressor, the method comprising:
determining a desired distribution of an angle of flow adjacent a leading edge of a corresponding blade of an adjacent rotor of the compressor;
determining a variation in flow speed and in radial distance from a rotational axis of the compressor between corresponding points of the leading edge of the blade and of a trailing edge of the vane;
determining a desired distribution of the angle of flow adjacent the trailing edge of the vane from the desired distribution of the angle of flow adjacent the leading edge of the blade and from the variation in flow speed and in radial distance; and
selecting a twist angle distribution corresponding or approximately corresponding to the desired distribution of the angle of flow adjacent the trailing edge of the vane.