Патент USA US3035421код для вставки
May 22,- 1962 3,035,413 E. T. LINDEROTH THERMODYNAMIC COMBUSTION DEVICE USING PULSATING GAS PRESSURE Original Filed Jan. 17, 1950 3 Sheets-Sheet 2 w.m T.m L mbma MW”MDWMMfRahWmHM May 22, 1962 E. T. LINDEROTH THERMODYNAMIC COMBUSTION DEVICE USING PULSATINGGAS PRESSURE Original Filed Jan. 17. 1950 17129“. 7 .35 35 ,‘ 30a 32 J , ' *@ a7 s Sheets-Sheet 3 a 86 3/ 5b 3,035,413 .306 .71 ' C7 ' s ‘* PRESU TIME BY Arryk. States Patent "‘ ice 3,635,413 Patented May 22, 1962 1 2 3,035,413 pure air is a special con?guration of the combustion chamber and of the air inlet which permits a suction relatively free of turbulence and a storage of fuel-free air THERMODYNAMIC CUMBUSTION DEVICE USING PULSATING GAS PRESSURE Erik Torvald Linderoth, N. Malarstrand 60, Stockholm, Sweden Original application Jan. 17, 1950, Ser. No. 139,015, now Patent No. 2,727,535, dated Dec. 20, 1955. Divided and this application Nov. 7, 1955, Ser. No. 553,169 Claims priority, application Sweden Jan. 29, 1949 8 Claims. (Cl. Gil-69.77) The present invention relates to a thermodynamic blast device preferably for generation of power, e.g., jet pro pulsion, but it may also ?nd general use wherever a strong blowing e?ect obtained by the consumption of heat may be useful. as well as fuel-admixed air in the combustion chamber without appreciable intermixing of them. Such inter mixing and turbulence in the combustion chamber is deferred to a subsequent phase of the operating cycle by the action of the above-named combustion accelerating means. Thus, since fuel air mixture which is ignited is not admixed with combustion residues in advance, the effect of the combustion accelerating means will be en hanced and a very abrupt increase of pressure will be ob tained. The various means described generally above and which will be described in more detail below, are complementary to each other and cooperate to serve a common pose, viz. This application is a division of my application, Serial to obtain a thermodynamic blast device operating with bio/139,015, ?led January 17, 1950, now Patent No. intermittent combustion, in which, notwithstanding the 2,727,535 issued on December 20, 1955. use of continuously open combustion chambers, high ex The present invention is concerned with the type of thermodynamic blast devices in which the pressure is 20 plosive pressures may be obtained. The invention is illustrated by the accompanying draw caused to pulsate by intermittent heating, and if desired, ings in which: by alternate heating and cooling of a gaseous medium, FIG. 1 shows a venturi tube having an edge for the the heating being achieved by intermittent combustion in constriction of the reverse flow. a combustion chamber in which the pressure pulsations FIG. 2 is a fragmentary sectional view showing the 25 are produced. sharp reverse flow resisting edge on an enlarged scale. Such thermodynamic blast devices, e.g. so-called pulse FIG. 3 is a view in axial section showing a modi?ed jets, operate with permanently open gas outlets. As a re form of venturi tube in which the sharp edge is so shaped sult thereof, it is not possible to obtain high explosive and arranged that a powerful constriction of the gas pressures in the combustion chambers, particularly as the permanently open gas outlets must be given a rela 30 stream is obtained for resisting reverse flow. tively large area of ?ow to permit a rapid exhausting of remaining combustion residues, which must be evacuated to make way for a new fuel air mixture. PEG. 4 shows means for controlling the supply of fuel. FIG. 5 is an enlarged fragmentary sectional view show ing a modi?cation of FIG. 4. This type of jet propulsion has heretofore exhibited a FIG. 6 is a transverse sectional view taken along the very low efficiency compared to the turbojets now used. 35 line VI—VI of FIG. 5. This disadvantage becomes still more marked if in order FIG. 7 is a longitudinal sectional view of a complete to avoid any moving parts it is attempted to construct a multi-chambered combustion device using a group of de pulse jet with the air inlet also permanently open. The vices as shown in FIGS. 5 and 6. increase of pressure by the intermittent combustion will 40 FIG. 8 is a transverse sectional view of the device then be still lower. shown in FIG. 7. The present invention has for its main object to avoid FIG. 9 is an enlarged view of one of the asymmetrical this disadvantage by providing means for achieving a ly ?ow resistant nozzles of FIGS. 7 and 8. very rapid ignition and rapid combustion of the fuel air FIG. 10 is a time-pressure graph illustrating the over mixture in the combustion chambers so that, in spite of a permanently open gas outlet and optionally a permanently 45 lapping polyphase power pulsations of the multi-charn bered device shown in FIGS. 7 and 8. open air inlet, high explosive pressures may be obtained. For comprehension of the inventive idea and the man Another object of the invention is to provide means ner of operation of the suggested devices reference is whereby it will be possible to use relatively small areas made to Bernoulli’s Theorem and to the manner of opera of ?ow in both the gas outlet and the air inlet, which makes it easier for the combustion accelerating device to 50 tion of a venturi tube. A common venturi tube is char acterized by a smoothly and gradually curved entrance produce the high explosive pressures which are the main portion and a long conical (diffuser-shaped) delivery purpose of this invention. portion. It is possible with such a tube to obtain very A further object of the invention is to provide means high velocities in the narrowest or throat section with whereby a certain quantity of pure air is sucked in both before and after aspiration of the fuel air mixture. The 55 a small resistance to ?ow, due to the recovery of pres sure that is obtained in the diffusor shaped delivery por purpose of the pure air is primarily to prevent direct con tion. In the entrance portion the pressure falls, thus tact between the aspirated fuel air mixture and the com transforming pressure energy to velocity energy and in bustion gases remaining in the combustion chamber. It the conical delivery portion a transformation of energy has been found that such contact may result in a prema ture ignition of the aspirated fuel air mixture which would 60 in the opposite direction is carried out, i.e. from velocity cause the igniting and combustion accelerating means ac cording to this invention to be less effective or even in operative. to pressure. According to the present invention a recovery of pres sure during ?ow in the reverse direction is prevented In addition, the intake of pure air referred to above 65 by an annular sharp forwardly directed edge 2, FIGS. 1 and 2, being ?tted at the narrowest section of the aims at eliminating another disadvantage inherent in venturi tube 1. The inlet portion is in the shape of a permanently open gas outlets and air inlets, viz. an exhaust curvedly ?aring funnel having a radius of curvature R ing of unburnt or partially burned fuel air mixture during and terminating at its small end in the forwardly directed the ?rst phase of a combustion period before the entire sharp edge '2. When there is a flow in the reverse direc volume of combustible gas in the combustion chamber 70 tion, this sharp edge causes the flow to be disengaged has been completely burnt. or diverted inwardly from the surface of the throat por The means utilized for achieving the desired intake of tion of the venturi tube, so that the air ?ow tends to 3,035,413 3 4 continue in a free jet of reduced cross sectional area reduced to a sharp-edged discharge nozzle 35 in the other chamber. as it passes rearwardly beyond the edge. When there is a flow in the forward direction, the flow is only slightly affected by the edge, if it is shaped as shown in FIGS. 1 and 2. The course of pressure will thus remain prac tically unchanged in the forward direction, while the resistance in the reverse direction is immensely increased. The resistance in the reverse direction can in the con The apparatus works as follows: It is started with com pressed air thus charging all the combustion chambers with a fuel-air mixture. Preferably, separate fuel injec tion nozzles S (FIG. 5) are used for starting, and ignition is then effected by means of electric spark plugs or glow plugs in one of the chambers. The combustion will then struction shown in FIGS. 1 and 2 be about 10 times spread through one of the pipes 33 to an adjacent com larger than the resistance in the forward direction. A . 10 bustion chamber, viz. the one into which the nozzle 35 necessary condition for this is that the venturi tube is opens. As shown in FIG. 9, the discharge nozzle 35 of so shaped that the widening angle of divergence of its the duct 33 is indicated as being sharp-edged at 35a. The conical part is at most 12.“, but preferably 5~10° and other end at 34 is rounded to permit free ?ow into the duct 33. By reason of this sharp-edged con?guration of that the ratio between the areas of the narrowest and widest sections is below the value 0.5 and preferably 15 its mouth, the nozzle 35 is asymmetrically ?ow-resistant. should be chosen between 0.3 and 0.1. The radius R The need for a positive acting check valve including a of the entrance portion should be at least 25% of the I bodily displaceable member is thus avoided. The trans smallest section diameter d and should preferably be fer of the combustion from one chamber to another chosen between 0.3 and 1d. D is the diameter of the takes a certain period of time, which is determined by the 20 ratio between the volume of the pipe 33 and the area of largest section. In the construction shown in FIG. 3 the flow separating the nozzle 35. After still another such a period of time edge 2 is ?tted a short distance in front of the narrowest the combustion has reached the third combustion cham part of the venturi tube and shaped like a nozzle having ber etc. When the combustion has reached the last approximately the same inner diameter as the venturi chamber, the first one has been recharged with a new tube. Between said nozzle and the narrowest section of 25 fuel-air mixture due to the suction effect of the ejector, the venturi tube there is an enlarged portion. and the ejector has during this period received ?ve power Through this shape not only a disengagement of the impulses. The combustion will thus continuously travel around the circle of combustion chambers and cause ?ow in the reverse direction is obtained, but also a strong constriction of the emerging jet, the smallest section of which can be reduced to 55% of the passage area of the 30 nozzle 2. In forward ?ow, on the other hand, there is no constriction. Some increase in the resistance in the for ward direction is, however, obtained, for which reason the distance I from the mouth of the venturi tube to its narrow est section should not exceed three times the mouth diam eter d1 and the smallest diameter d2 of the venturi tube should lie between 0.70 to 1.1, and preferably between successive explosions at equal intervals. FIG. 7 shows how the successive power impulses com— bine to produce a substantially constant thrust. An essen tial advantage reached by the ignition being effected through injection of combustion gases from one chamber to the other is, that the combustion is hereby strongly accelerated, which is of the utmost importance in this case, when high explosive pressure is desired in chambers which are constantly in connection with the atmosphere, and where the suction losses are small due to the venturi 0.8 and 1.0. shape, thus causing slight turbulence. FIGS. 5 and 6 show a modi?cation of the apparatus of FIG. 4 and a complete multi-chambered device using 4.0 For the previously described purposes a too violent ignition is not desirable with respect to silent operation. ?ve of these units is shown in FIGS. 7 and 8. Referring to FIGS. 7 and 8, ?ve venturi tubes 1d serving as combustion chambers are mounted in a circle In jet propulsion, though, the power output is of greater importance than silent operation. The large ejector, how around an ejector comprising a series of secondary air ever, provides a silencing effect to a certain extent, if it nozzles 30a which serve ?rstly to cooperate in drawing 45 is composed by a large number of relatively short nozzles of different lengths, so that resonance phenomena cannot out remaining combustion gases from the combustion occur. The streamlined casing 36 enclosing the apparatus chambers, and secondly to accelerate a quantity of air also contributes to the silencing etfect. The main purpose which is many times larger than the quantity of air taking of said casing 36 is to catch the wind by means of a part in the combustion, thus considerably increasing the motive power. The gases ?owing from the combustion 50 diffuser-shaped air inlet 37 in its front end and transfer the ram pressure thus obtained to the jet power unit. chambers are de?ected rearwardly by the curved discharge So as to permit the power unit to utilize the ram pres nozzles 5b which are interconnected with the central sure in the best possible way the area of the discharge ejector 30a. Thus the directions of discharge of the nozzle should not be greater than the area of the air in reverse ?ow as well as the main ?ow coincide. The re verse flow from the venturi tubes is injected in the sec 55 take through the venturi tube. Preferably the area of the discharge port should be 0.5 to 1 of the intake of the ondary nozzles 30b mounted around the central ejector venturi tube. and connected thereto. The combustion chambers and the discharge nozzles are surrounded by cooling jackets A condition precedent for the combustion properly travelling around as described above is, that a certain 60 quantity of air is drawn in both before and after the quently draws in cooling air. fuel is supplied so as to ‘avoid self-ignitions, and that the The fuel is supplied through an annular distribution transfer pipes 33 are constructed as indicated above, i.e. chamber 31 (FIGS. 5 and 6) to a plurality of bores 32 with a smoothly curved admission portion and a delivery circumferentially spaced around the narrowest section of the venturi tube. The fuel supply is otherwise con portion so shaped that constriction is obtained in the trolled by ball valves in the manner hereinafter described 65 reverse direction. Through this constriction and the sub 8b, connected to the central ejector 30a which conse in connection with FIG. 4, so as to ensure that there is a mass of air containing no fuel on either side of the fuel sequent formation of turbulence the ?arne emerging in air mixture at the moment of ignition. As in this case through the entire length of the pipe 33, while the smooth ly curved admission portion gives a smooth ?ow in the the most violent explosions possible are desired, in order to obtain high explosion pressures, the following arrange the reverse direction will be very short and will not reach opposite direction and a slow combustion so that the ?ame reaches the sharp-edged nozzle 35 and ignites the gas body in the combustion chamber. A further condi the adjacent chamber, said pipe having a smoothly curved tion for the operation of the device is that the transfer admission part 34 connected to one chamber and being 76 pipes are cooled to a temperature lying slightly below ment may be effected. From each combustion chamber a pipe 33 is drawn to 3,035,413 5 6 the ignition temperature of the gas mixture. For this reason they are provided with cooling ?anges 38. wardly with respect to said chamber, said lip being di Also the combustion chambers should be cooled down to below the ignition temperature of the fuel-air mixture. Cooling ?anges are not required, however, except at the rected toward said chamber for providing an asymmetrical ?ow resistance opposing reverse ?ow through said inlet, a fuel supply duct communicating with said chamber, a metering valve included in said duct, said valve including portion lying nearest the discharge nozzles 5b. Obviously, the number of combustion chambers may a check member which shuts off fuel ?ow into said cham her through said duct after a predetermined volume of be other than ?ve. fuel has been admitted into said chamber, said check member being resettable by an increase in pressure within As illustrated in FIG. 10, the ?rings of the several chambers are displaced in phase because they ?re suc 10 said chamber to permit a repeated flow of ‘fuel in said duct, ignition means for repeatedly igniting a combus cessively. As a result, there is a series of pressure peaks which partially overlap each other with a resulting con tible air-fuel mixture in said chamber, said mixture being formed by said ‘fuel and by air entering said chamber tinuity of pressure. The individual pressure pulsations through said inlet, and exhaust means communicating are thus suppressed or ?ltered out in the combined output of the ?ve chambers. 15 with said chamber for removing the products of combus tion produced by ignition of said mixture. Having now particularly described the nature of my 6. A thermodynamic blast device comprising a plural invention and the manner of its operation what I claim is: ity of combustion chambers arranged in an endless series, l. A thermodynamic blast device comprising a plural each chamber being adapted for intermittent combustion ity of combustion chambers arranged in an endless series, each chamber being adapted for intermittent combustion 20 and each having a gas outlet and an air inlet, adjacent ones of said combustion chambers being interconnected and each having a ‘gas outlet and ‘an air inlet, each air with each other by means of continuous open ducts, inlet being in continuous communication with the atmos whereby said ducts and said chambers form a closed cir phere, adjacent ones of said combustion chambers being cuit, each one of said ducts having a flow restricting ?rst interconnected with each other by means of ducts whereby said ducts and said chambers form a closed circuit, each 25 end including an asymmetrically ?ow-resistant nozzle and a second end shaped to permit free ?ow into said duct, one of said ducts having a sharp-edged ?ow restricting said ends of each duct being connected to said two adja ?rst end constituted by an asymmetrically ?ow-resistant cent ones of said chambers between which said duct ex nozzle and a second end shaped to permit free ?ow into tends, said duct ends permitting the ?ow of an igniting said duct, said ends of each duct being connected to said and combustion accelerating ?ame around said closed two adjacent ones of said chambers between which said circuit in one direction and opposing the ?ow of said duct extends, said duct ends permitting the ?ow of an igniting and combustion accelerating ?ame around said flame in the opposite direction, whereby combustion gases in said chambers may be repeatedly ?red in a cyclical manner, the gases in the several chambers being ?red gases in said chambers may be repeatedly ?red in a 35 consecutively in a predetermined sequence. 7. A thermodynamic blast device according to claim 6, cyclical manner, the gases in the several chambers being in which each of said combustion chambers is elongated ?red consecutively in a predetermined sequence. and comprises a venturi-shaped portion which de?nes said 2. A thermodynamic blast device according to claim 1, continuous air inlet passage, the throat portion of said wherein said second end of each duct is enlarged and connected to said combustion chamber by means of a 40 inlet passage comprising an annular knife-edged projec tion offering an asymmetrical aerodynamic resistance to ?aring and smoothly rounded funnel-shaped part. the flow of gas through said throat portion, said knife 3. A thermodynamic blast device according to claim 1, edge being directed forwardly with respect to combustion including a common central ejector around which all of air entering said chamber to minimize resistance to in said combustion chambers are arranged and into which said gas outlets open, and cooling jackets surrounding the 45 ward ?ow and to oppose the outward ?ow of combustion gases from said chamber. combustion chambers and in communication with said 8. A thermodynamic blast device according to claim 7, central ejector in order to cool said chambers below the in which said venturi-shaped portion extends beyond said ignition temperature of the fuel air mixture. throat portion exteriorly of said chamber. 4. A thermodynamic blast device according to claim 1, further comprising individual fuel injection means com 50 municating with each combustion chamber, a fuel supply References Cited in the ?le of this patent conduit connected to each fuel injection means, and two UNITED STATES PATENTS check valves arranged in each fuel supply conduit, one of 2,404,335 Whittle ______________ __ July 16, 1946 said check valves closing in the direction in which the Serrell ______________ __ Mar. 14, 1950 fuel is supplied, the other of said check valves closing in 55 2,500,712 2,612,749 Tenney et al ____________ __ Oct. 7, 1952 the opposite direction, the ?rst-mentioned check valve 2,639,580 Stuart ______________ __ May 26, 1953 being biased to be normally kept open ‘and to limit 2,674,091 Malick _______________ __ Apr. 6, 1954 the ?ow of fuel for each of the pressure pulsations in the combustion chamber to which its associated fuel injec FOREIGN PATENTS 60 closed circuit in one direction and opposing the ?ow of said ?ame in the opposite direction, whereby combustion tion means is connected. 5. A pulsating thermodynamic blast device comprising a combustion chamber, a continuously open air inlet for said combustion chamber through which said chamber communicates with the atmosphere, said inlet having a constricted throat portion, an annular sharp-edged lip ex 518,453 559,370 630,180 616,481 Germany ____________ __ Feb. Germany ____________ __ Sept. Germany ____________ __ Sept. Great Britain _________ .__ Jan. 16, 21, 24, 21, 1931 1932 1936 1949 OTHER REFERENCES tending around the periphery of said throat portion, said US. Navy Project “Squid,” Technical Memorandum throat portion being smoothly rounded to provide a pro No. 4, “The Aero'Resonator Power Plant of the V-l gressively increasing cross-sectional area for said inlet Flying Bomb,” by Ing. Guenther Diedrich, June 30, 1948, proceeding away from said lip both inwardly and out 70 Princeton, University, page 39, Fig. 55.