US2430399A

US2430399A - Jet augmenter for combustion turbine propulsion plants

Info

Publication number: US2430399A
Application number: US502035A
Authority: US
Inventors: Heppner Fritz Albert Max
Original assignee: Armstrong Siddeley Motors Ltd
Current assignee: Armstrong Siddeley Motors Ltd
Priority date: 1942-11-05
Filing date: 1943-09-11
Publication date: 1947-11-04
Anticipated expiration: 1964-11-04

Description

Nov. 4, 1947. F. A. M. HEPPNER 2,430,399

JET AUGMENTERFOR COMBUSTION TURBINE PROPULSION PLANTS Filed Sept. 11, 1943 3 Sheets-Sheet 1 Nov. 4, 1947. F, M, HE NER 2,430,399

JET AUGMENTER FOR COMBUSTION TURBINE PROPULSION PLANTS 1 (IIIIIIIIIIIIIIII //v VE/V'TO R 3 Mai MM.

.7 Ma farm T'TOK/YEY Patented Nov. 4, 1947 JET AUGMENTER FOR COIVIBUSTION TURBINE PROPULSION PLANTS Fritz Albert Max Heppner, Leamington Spa,

England, assignor to Armstrong Siddeley Motors Limited, Coventry, England Application September 11, 1943, Serial No. 502,035 In Great Britain November 5, 1942 This invention relates to a compound internalcombustion turbine plant for jet-propulsion purposes, a non-compound internal-combustion turbine plant being disclosed in Patent No. 2,416,389, issued February 25, 1947. v

The invention consists in a compound plant having independent compressor rotors which are respectively coupled, for rotation in unison therewith, to rotary turbine sections the blades of which coact with blades on a contra-rotating turbine member which drives the rotary portion of a jet-augmenter.

Preferably the turbine and compressor are of the axial flow type, the turbine preferably being radially outwardly of the compressor, in which case the said turbine member can be arranged to be in the form of a shell to surround the compressor or a portion thereof, and to carry the rotary jet-augmenter blades externally. Conveniently, too, the flow through the compressor is in the opposite direction to that through the turbine.

In the drawings, Figs. 1, 2 and 3 are respectively diagrammatic views showing different arrangements of the compressor, turbine and augmenter that may be employed in the present invention;

Figs. 4 and 5' are axial sections through the compressor, turbine and augmenter of two other embodiments of the present invention;

Fig. 5a is a diagram to illustrate the blading and direction of rotation of the embodiment of Fig.

Figs. 6 and 7 are axial sections through the compressor, turbine and augmenter of yet other embodiments of the present invention.

As far as possible like reference numerals are applied throughout the various figures to denote similar parts.

In the construction of Figure 1 there is a stationary shaft 20 on which are journalled independent rotors 2|, 22 and 23 of a compressor the stationary, coacting, bladed portions of which are carried by a shell [9. The rotors are mechanically coupled to

turbine sections

24, 25 and 26, respectively. The three turbine sections have blades which coact with blades 21 on a counterrotating turbine shell 28 carrying externally jetaugmenter blades 29 which coact with stationary augmenter blades 30.

8 Claims. (01. 6035.6)

ber 32 (comprising in this case a plurality of singl chambers arranged in a circle round the axis of the plant) before entering the turbine.

As will be well understood, the exhaust of the turbine and the exhaust of the augmenter, as indicated by the arrows, unite to form the propulsion jet.

In the construction of Figure 2 there is again a stationary shaft 20 upon which-are mounted the rotors 2|, 22 and 23 of three compressor sectlons, and a shell IS on which are carried the stationary, coacting blades. The compressor rotors are mechanically coupled to

turbine sections

24, 25 and '26 the blades of all of which coact with blade rows 21 on a contra-rotating turbine shell 28 which carries externally et-augmenter blade rows 29 coacting with stationary augmenter blade rows 30 carried by shell [9.

Part of the air compressed by the augmenter is delivered to the first compressor section 2| through a plurality of tubular members I! and thence to the second and third sections, a indicated by the arrows, after which combustion is effected in the combustion chamber, indicated at 32 at the tail-end of the plant, the burning gases then travelling with reversed flow, as shown by the arrows, through a plurality of curved pipes I6, connecting passage l8a formed in the annular shell I8, and pipes 3| to the inlet of the turbine, whilst the exhaust of the latter and the remainder of the air compressed in the augl'nenter constitute the propulsion jet.

In the construction of Figure 3 there is a series of independent rotary compressor sections of which only three are shown in full lines, being marked 21, 22 and 23, and these are mechanically coupled with

turbine sections

24, 25 and 26, respectively. The coacting compressor blade rows 34 are stationary, whilst the coacting turbine blad rows 21 are fast with the shaft 35 and rotate in the direction opposite to that in which the turbine sections 24-26 rotate. The shaft 35 carries rotary jet-augmenter blades 29 which oo- The compressor flow is indicated by the aract with stationary augmenter blades 30.

It will be observed that the compressor in this case is arranged to be radially outwardly of the turbine, air for the compressor being taken in from the jet-augmenter through the tubular member I1 and, on leaving the compressor, being reversed in the combustion chamber, indicated at 32 at the tail-end of the plant, before entering the turbine. The exhaust from the turbine is again reversed in flow, asindicated by the arrows, to join the remainder of the air compressed by the augmenter and to constitute the propulsion Jet.

In the construction of Figure 4; there is again a stationary shaft 20 upon which are mounted a number of independent rotary compressor portions of which three are marked 2|, 22 and 23. These are respectively coupled with

turbine sections

24, 25 and 26 the blades of which coact with contra-rotating turbine blade rows 21 on a shell 28, The latter carries externally rows of jetaugmenter blades 29 coacting with stationary augmenter blades 30. Stationary compressor blades 34 are mounted on the shaft 28.

In this construction the air for the compressor is taken in at 36, and after traversing the compressor it is reversed in the combustion chamber, indicated at 32, before being passed to the turbine.

The outlet from the turbine is passed through passages formed in stationary, intake vanes 38 of the augmenter, the latter being hollow, and in due course, as indicated by the arrows, it mingles with the delivery from the augmenter to constitute the propulsion jet.

The construction of Figure has much in common with that of Figure 4, except that, in Figure 5, in addition to the contra-rotating shell 28 there is also contra-rotation between adjacent combined turbine and compressor blade rows. The blading and direction of rotation are illustrated in Figure 5a.

Thus, it will be observed that there are compressor portions such as those marked 2|, 22 and 23 respectively coupled with turbine portions such as those marked 24, 25 and 26, which all rotate in one direction, being journalled upon the stationary shaft 20, and coacting with these turbine portions are blades 21 on a counter-rotating shell 28 which carries externally the rows of augmenter blades 29 coacting with the stationary augmenter blade rows 38. In addition, there are stationary turbine blade rows 48 and there are other turbine blade rows such as those marked 4 I, 42 and 43 respectively coupled to compressor sections such as those marked 44, 45 and 46 rotating in the same direction as the shell 28.

Air for the compressor is taken in at 33, being reversed in the combustion chamber, indicated at 32 at the tail-end of the plant, before being delivered to the turbine. The exhaust from the latter is again led through stationary intake vanes 38, of the augmenter, which are hollow, as indicated by the arrows, and in due course it mingles with the delivery from the augmenter, to constitute the propulsion jet.

In the. construction of Figure 6 there are again rotary compressor sections 2|, 22 and 23 journailed upon a stationary shaft 28 and respectively coupled to

turbine portions

24, 25 and 26 the blades of which coact with turbine blade rows 21 carried by a short shell 28a driving rotary augmenter blades 29 coacting with stationary augmenter blades 38, and in this case one of the turbine blade rows 21 is fast with the row 48 of compressor blades which is journalled upon the shaft 20 and rotates in the opposite direction to the

compressor sections

2 I, 22 and 23. The stationary compressor blades are indicated at 34.

Air for the compressor is introduced at 36 and is reversed in the combustion chamber, indicated at 32 at the tail-end of the plant, before being delivered to the turbine whilst the exhaust from the latter is again reversed in flow by passage l4 and mingles with the augmenter air to constitute the propulsion jet.

Substantially the same arrangement is disclosed in Figure 7, except that there are two rows 21 of counter-rotating turbine blades which are respectively coupled to two rows 48 of compressor blades. Furthermore, in this case the exhaust from the turbine is taken through passages formed in stationary intake vanes 38, of the augmenter, which are hollow, and finally passed through similar passages formed in stationary outlet vanes 50 of the augmenter to join the air of the latter and constitute the propulsion jet. This serves for equalizing the temperatures of the augmenter air and the turbine exhaust, and thereby increases the sound speed limit of the mixture in the nozzle. The pressures of the two fluids when mixing should be substantially the same, in order to avoid shock, and a small difference in the speeds will cause only negligible losses and in many cases may be advisable. If the augmenter blades are steep ones, i. e., at negative incidence for the designed speed, satisfactory operation will be obtained when climbing.

The constructions of Figures 6 and 7 have much in common with that disclosed in the specification accompanying my co-pending patent application Serial No. 500,694, filed August 31, 1943.

The plant is short, light and very compact with substantially no unused space. It provides for good auxiliary drives and the turbine is short and efiicient, whilst few labyrinths only are required. The stressing is good and excellent mixing of the turbine exhaust and augmenter air can be obtained.

The general theory of the multi-compound engine requires that most of the useful energy shall be taken out mechanically, i. e., that the main part of the propulsive effort (as regards a jet-pro pulsion plant) shall be provided by a jet-augmenter. In the latter the incoming air is slowed down and its pressure, by a ram effect, is increased. After compression in the augmenter the air is expanded in the jet nozzle. When an aircraft with such an engine is climbing, however, the ram effect is negligible and the overall pressure ratio in the augmenter drops considerably and the jet diameter tends to become too small. This effect would be worse if the jet were supersonic with a diverging nozzle because the jet would then be reduced to the smallest cross-section of the nozzle and no expansion in the diverging part of the nozzle could take place, inasmuch as owing to the lack of ram pressure the overall pressure ratio in the augmenter would have dropped. But whereas sound speed is the limit for the speed of the jet of an augmenter engine, taking into consideration both climbing and the possibility of regulation, a comparatively high jet speed is desirable to give the augmenter air the maximum amount of overall acceleration whereby to avoid too great a percentage of intake losses. As stated, however, by mixing the hot gases of the turbine exhaust with the augmenter air the sound speed limit in the nozzle is increased.

The above conditions require a large slowlyrotating augmenter and by driving this from a contra-rotating turbine shell such as 28 or 28a the turbine can have high relative speed without excessive stresses. The necessary reaction torque is preferably provided by the reaction of the whole compressor, and for a very high compression ratio this is just enough. From desi n considerations this point is very satisfactory with regard to the non-stall condition of a regulation compound engine. In general, the sound speed and performance conditions appear to exclude the satisfactory use of small-diameter engines because of restriction to mass flow.

It is, therefore, important to keep the overall length short, rather than to reduce the diameter of the plant, and, as regards head resistance, it should be noted that all the resistance is skin friction only and that no form drag can develop.

What I claim as my invention and desire to secure by Letters Patent of the United States is:

1. A compound internal-combustion turbine plant for jet propulsion purposes including a plurality of independent compressor sections through which the fluid flows in series, a combustion chamber communicating with the end compressor section of said series, a plurality of turbine sections arranged in series and communicating with the outlet of said chamber, said turbine sections being respectively coupled to said compressorr sections to drive the same, a turbine member rotating in the direction opposite to said turbine sections, blades coacti'ng with all of said turbine sections carried by said member, a jet augmenter including blades driven by said member, a jet duct, means for conveying fluid from the end turbine section of said series to said :Iet duct, and means for conveying fluid from said augmenter to said duct.

2. A turbine plant according to claim 1 in which the turbine member is a rotatable shell and the blades driven thereby are mounted externally thereon,

3. A turbine plant according to claim 1 in which the compressor sections and the turbine sections are arranged for axial flow of the fluid therethrough and in which the turbine sections and the compressor sections are arranged at different radii with one surrounding the other.

4. A compound internal-combustion engine plant for jet propulsion purposes including a plurality of independent compressor sections through which the fluid flows axially in series, a combustion chamber communicating with the end compressor section of the series, a plurality of turbine sections arranged in series for axial 6 flow of the fluid therethrough and communicating with the outlet of said chamber, said turbine sections being respectively coupled to said compressor sections to drive the same, said turbine sections being disposed radially outwardly of said compressor sections, a shell rotating in the direction opposite to said turbine sections, blades carried internally by said shell and coacting with blades of all of said turbine sections, a jet augmenter including blades carried externally by said shell, a jet duct, means for conveying fluid from the end turbine section of said series to said jet duct, and means for conveying fluid from said augmenter to said duct.

5. A turbine plant according to claim 4 in which the means for conveying fluid from the end turbine section to the jet duct reverses the direction of flow of the fluid.

6. A turbine plant according to claim 4 in which the means for conveying fluid from the end turbine section to the jet duct reverses the direction of flow of the fluid and passes around said augmenter.

7. A turbine plant according to claim 4 in which the augmenter includes stationary vanes having passages therein and the means for conveying fluid from the end turbine section to the jet duct includes the passages through said stationary vanes.

8. A turbine plant according to claim 4 having between two of said compressor sections a further compressor section which is mechanically coupled to said shell.

FRITZ ALBERT MAX HEPPNER.

REFERENCES CITED The following references are of record in the me of this patent:

UNITED STATES PATENTS