US2589548A

US2589548A - Jet propulsion plant

Info

Publication number: US2589548A
Application number: US735676A
Authority: US
Inventors: Imbert Roger Jean
Original assignee: Rateau SA
Current assignee: Rateau SA
Priority date: 1946-04-02
Filing date: 1947-03-19
Publication date: 1952-03-18
Anticipated expiration: 1969-03-18

Description

March 18, 1952 R. J. IMBERT JET PROPULSION PLANT 2 SHEETSSHEET 1 Filed March 19, 1947 n I disig-nce A -Frg5 95am mam IN l/eNTo R a C w e Md e mwro 3 K m m o m 8 s c141 i nder he March is, 1952 R. J. IMBERT 2,589,548 JET PROPULSION PLANT Filed March 19, 1947 2 SHEETS-SHEET 2' IN VQN'TO R Patented Mar. 18, 1952 UNITED PATENT OFFICE .JETBROPULSION PLANT "Rogerflejan t lmbert, Paris, France, assignor to S'ociete iB a'teau (Societe Anony ne), Paris, 1=rane, a pompany of France and 'Rene Anxionnaz 'Paris, :France, jointly ApplicationfMarch 19, 1Qg1 7 erialNo. 735,676

. In r nna- 9 'CIa m (onto-eas In the prior U. S. Patent 2,396,911'ofwhicnIjam one of the applicants, and relatinggto jet. propulsion plants for aircraft, there is describeda plant in which the cylinders of an internal combustion reciprocating engine driving theair compressor are cooled by the flow of "air passing through the propulsion nozzle. The output of air reguire'd'ior propelling purposes is substantially higher than the amount of air which isv sufficient for ensuring this cooling. It is thereforenecessary to improve the efliciency of the propeller by limiting the output of the cooling air to itsoptimum value. The arrangements which are capable of, ensuring a limitation of this flow and improving'the cooling conditions of the engine form theobject of the U. S. application Serial No. 643,02s filedby Marcel Sdille on January 24,1946, forimprover nents in Reaction Propellers. Inthis application, the flow of air delivered by the compressor is divided into two parts of which one is projected towards the periphery and enters the-propulsion nozzle directly while the second, separated from the former bya suitable partitioning, is submitted to the action of a booster or fan which is-tomake up for the loss of pressure inthe cooling circuit and this second air flow passes through; the compartment occupied by the cylinders et'the engine and ensures the cooling; thereof.

My present invention has'for its object animprovement in the arrangement discl'osedhereinabove based on the separation-betweenfthe two flows, but it simplifies the arrangement by doing away with theauxiliary fan andensures a'greater adaptability in theoperation-of the plant.

The arrangementaccording. to-my invention also includes a partitionseparating the two flows,

.Fig, ti-illustrates a combinationof the adjustjment of the output and of the coolingflow and of the adjustment of the outer flow.

shows in partial cross-section, on an enlargedscale, the manner in which thedeviceof Fig. 4 may be controlled.

Fig. 6 illustrates a temperature measuring .device positioned in the engine.

Tnthe first arrangement, Fig. 1 shows .at can aircompressor and at c the reciprocating .engine which drives saidcompressor. The air delivered by the compressor is divided into two .cseparate flowsby a-partition bfsaid partition extending in this case up to the propulsion nozzle.

The inner flow is ledby the partitionito the engine c for coolingthe same. .The outerflow is led directly to the propulsion nozzle.

' 'In;the figure, the cooling flow receives past the 'enginecthe exhaust gases-from the said engine 20.

-c but these gases might as wellbe discharged intothe outer flow. It will be noted that it is possibleto heat the outer flow through theagency {of the combustion chambers e and to heat the inner-flow through burners .12 arranged :between the engine and the propulsion nozzle.

The adjustment of the cooling flow is obtained by "a movable obturator or throttle memberj of 'suitableout'line adapted to moveaxially so as to modify theoutputcrossesectionof the nozzle D2 ;of the-cooling'circuit. This throttle member is shown :in its maximum :opening position in :the

upper half of the cross-section and -in.its throttling position in its lower half .cross-section The translational movement of this throttle .:member':-is ensured through any known means but with an extension thereof toa point-at which the drop in pressure in the two-circuits becomes equal and it also allows usingainovable member adapted to modify the outputof the cooling-flow in accordance with thetemperature of the engine.

The following description and corresponding accompanying drawing given by way of example and by no means in alimitative: sense will allow a better understanding of :my invention.

In said drawing:

Fig. 1 is a diagrammatic axial .crossasectionzof a propeller executed in accordance with my invention and incorporating meansioradjusting the cooling flow at the output-of the. propeller.

Fig. 2 is a diagrammaticaxial. cross-sectional view of a modification of theadjusting means-for adjusting the cooling flow.

Fig. 3 is a diagram showing the positions of the adjusting member illustrated Fig, 2 correponding to qu libriumb tween o both gaseous flows.

such'asapiston g controlledin its turn by a dis- .tributorfihrunder theaction .of a thermostatk ac- .tuatedby the temperature of adelicate part of the enginesuch as a'valve seat. ;Any other form pf :execu'tion may -be., adopt e d as well.

This adjustment allows for instance keeping .:substantially constant the engine coolingcurrent spiteoiany variation in the-drop of pressure in th oute ircuit, which sirp inp e ma vary-accordingto therate o f gheating-of the outer flow through the combustion-performed at the burners e,-

Thi allows the ef r ma nta nin at su tab values the temperature of the engine and this latter variable factor may be used as disclosed hereinabpve asa base for the adjustment obtained with the obturator f,

Another possible embodimentoi my invention is shown in Fig. 2. In this case, the free crosssection area for the cooling fiownis vnot modified as in .the jpreceding case, but the point atwhich this cooling flow-mi'xes with the outer flow isdisplaced inside the expansion nozzle or in other words the pressure prevailing in the outlet of the cooling flow is modified to vary the output of cooling flow in accordance with the value of the said pressure;

The arrangement allowing this variable condition assumes for instance the shape of a cylindrical ferrule l adapted to move inside the exhaust nozzle with a translational movement and to this purpose the partition m ends with a cylindrical part m1 serving as a guide for the ferrule I.

In Fig. 2 the exhaust or of. the engine is connected with the chamber used for the outer flow, but it may as well open into the cooling flow downstream of the engine as in the case of Fig l.

The desired balance of pressure in the mixing cross-section of the two gasiform flows of the arrangement illustrated in Fig. 2 is checked by means of the graph of Fig. 3; starting from a static pressure prevailing at point 1. corresponding to the entrance of the air at A into the plant, .I obtain a pressure a at the output of the last wheel of the compressor. The pressure curve for the outer flow, illustrated by the curve 0 when said flow has not been heated, rises up to point 1 by reason of a slowing down effect in the channel following said last wheel after which it slopes downwardly until it reaches the point 11. where the static pressure is equal to the ambient pressure and corresponding to the output end of the propulsion nozzle. When the outer flow includes means for heating through combustion by means of burners e, the curve follows the dotted outline o1 underneath the line 0 precedingly considered by reason of an increase of the speed of flow.

. The pressure curve of the cooling flow is shown at T when no heating of this flow is provided and at 1-1 when the flow is submitted to a heating through a combustion operatedby the burners d.

The corresponding curves of the outer flow and of the cooling flow cross one another at four points: 12, x, y, 2 which define the respective positions to be occupied by the adjusting ferrule I, when the pressures of both flows at the mixing point are to be maintained equal, according to the rate of running of the plant. Of course, for a suitable position of the ferrule Z, it is possible, however, to have, at the mixing point, in the outer flow a pressure greater or smaller than that of the cooling flow and to vary in this manner the output of the cooling flow.

In my copending application Serial Number 643,027 filed on January 24, 1946, now Patent No. 2,557,435, for Regulating devices for the outlet section of a reaction propeller tube or nozzle, I have described a telescopic nozzle adapted to move axially with reference to the reaction nozzle. Fig. 4 shows how it is possible with such a nozzle to associate the adjustment of the position of the output nozzle of the cooling flow of gasiform fluid with the reduction in cross-section of the output nozzle of the outer flow, said association giving a still greater adaptability to the operation of the propulsion plant.

In this case, it is possible to use the movable ferrule Z of Fig. 2, but the latter instead of sliding directly inside the cylindrical end m1 of the partition separating the gasiform flows is carried hollow rod 92 of which slides on the rod of piston inside an intermediary ferrule 15 rigid with a nozzle u executed in accordance with the arrangement disclosed in the last mentioned application referred to hereinabove.

This arrangement allows obtaining the extreme positions shown in the lower and higher crosssections, and also any intermediary .positioribeg while the pressure fluid valve therefor is at in; said valve may be actuated in any manner, for example by hand.

What I claim is:

1. In a jet propulsion plant of the type comprising air compression means having at least one compression stage, an internal combustion reciprocating engine driving said air compressing means, and a propulsion nozzle fed by said air compressing means for producing the motive jet; an annular partition beginning at the de-- livery side of the said air compressing means after the last compressing stage of said air compressing means for dividing the air delivered by the last compression stage into two separate flows, one of which is led inside said partition around the engine for cooling the same, and the other of which is by-passed outside of said partition towards the propulsion nozzle, said partition having a discharge end near the propulsion nozzle, heating means outside of said partition between the said last stage and the discharge end of the partition for heating said second mentioned flow, and means near the discharge end of said partition for regulating the cooling flow inside said partition.

2. The combination of claim 1, wherein heating means are provided in the cooling flow between the engine and the end of said partition.

3. The combination of claim 1, wherein the regulating means for the cooling flow comprises a movable throttling member for varying the output of the cooling flow.

4. The combination of claim 1 comprising further temperature sensitive means arranged in the vicinity of the valves of the said engine, the regulating means for the cooling flow being controlled by said temperature sensitive means.

5. In a jet propulsion plant of the type comprising air compressing means having at least one compression stage, an internal combustion reciprocating engine driving said means, and a propulsion nozzle fed by said compressing means for producing the motive jet; a partition beginning at the delivery side of the said compressing means after the last compression stage thereof for dividing .the air delivered by said stage into two separate flows, one of which is led inside said partition around the engine for cooling the same, and the other of which is by-passed outside said partition towards the propulsion nozzle, said partition having a discharge end near the propulsion nozzle, heating means provided in the outer by-passed flow as well as in the cooling flow between the engine and the discharge end of the partition and a movable throttling member arranged near the discharge end of the said partition for varying'the output of the cooling flow inside said partition.

'6. In a jet propulsion plant of the type comprising air compressing means having at least one compression stage, an internal combustion reciprocating engine driving said air compressing means, and a propulsion nozzle fed by said air compressing means for producing the motive jet; an annular partition beginning at the delivery side of the said air compressing means after the last compression stage for dividing the air delivered by the last compression stage into two separate flows, one of which is led inside said partition around the engine for cooling the same, and the other of which is by-passed outside said partition towards the propulsion nozzle, said partition having a discharge end ahead of the propulsion nozzle, heating means outside of said partition for heating the second mentioned flow, and a movable ring at the discharge end of said partition for variably prolonging the same towards the propulsion nozzle, said ring having a diameter less than that of the outlet port of said nozzle, so that an annular passage for the outer by-passed flow remains open between said rin and said nozzle for each position of said ring.

7. The combination of claim 6, wherein heating means are also provided in thecooling flow between the engine and the end of said partition.

8. The combination of claim 6, wherein the movable ring comprises at least two parts annular 25 telescopically arranged, one of said parts'having further an annular nozzle adapted to cooperate 6 with the propulsion nozzle for varying the crosssection area thereof.

9. The combination of claim 6, comprising further temperature sensitive means arranged in the vicinity of the valves of the said engine, the displacement of the said movable wall being controlled by said temperature sensitive means.

ROGER JEAN IMBERT.

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

UNITED :STATES PATENTS Number Name Date 2,129,826 Dintilhac Sept. 13, 1938 2,150,143 Adams Mar. 14, 1939 2,396,911 Anxionnaz et a1. Mar. 19, 1946 2,407,719 Melchior Sept. 17, 1946 2,455,385 Scha i rer Dec. 7, 1948 2,458,600 Imbertet a1 Jan. 11, 1949 FOREIGN PATENTS Number Country Date 844,442 France Apr. 24, 1939