JPH04507132A - Method and apparatus for controlling fluid dynamic mixing in a pulse combustor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Method and apparatus for controlling fluid dynamic mixing in a pulse combustor Background of the invention The present invention is generally applicable to the control of pulse combustors (Pulse cosbustors). related. The present invention particularly relates to combustion reactants in pulse combustors. on reaetants) and combustion products (coIIbustion prod ucts) to control the fluid dynamic mixing of The present invention relates to a method and apparatus. The government is United Stin Departmentφ of Energy and A.T. Technology Inc. Presented by Horated (AT&T Technologies, Inc.) Pursuant to contract clause DE-ACO4-713DPO0789, the present invention is have the right to

A pulse combustor generally has a combustion chamber (CO bust tonchamber) and , an inlet for admitting combustion reactants (typically fuel and air) into the combustion chamber; , and an outlet for discharging combustion products from the combustion chamber. Pulse combustor A charge of sintered reactants is placed in the combustion chamber, ignites, and releases combustion products. The first ignition is preferably by a spark plug. It will be assisted. The products of combustion spread out through the outlet, thereby causing a portion inside the combustion chamber. creates a vacuum of new combustion reactants for the next cycle. Helps draw the charge into the combustion chamber. The new charge is burned from the previous cycle It is ignited by mixing with the product. Therefore, after the first ignition, the operation is Self-sufficient.

Compared to conventional combustion systems, pulse combustors offer attractive attributes such as: has. In other words, it has 2 to 3 times higher heat transfer, one rank higher grade (an order r　magnitudehtgher) combustion intensity, one-third nitrogen oxidation Capable of material evacuation, forty percent (40%) higher thermal efficiency, and self-suction That's true. The combination of these attributes makes traditional combustor Excellent cost performance (economic trader) f'). Furthermore, the oscillating flow field in the pulse combustor (osclllat The enhanced heat and mass transfer associated with It can provide important improvements to industrial and chemical processes. But long A potential disadvantage of pulse combustors is that they have a wide range of energy release rates (per unit time). (hereinafter the same) (energy releases) Points where operation is not possible (i.e. their turndown ratio) ios) is limited) and can vary widely regionally and temporally. The point is that it is sensitive to the nature of combustion.

There are various different types of pulse combustors (i.e. quarter wave or pulse combustor). Schmldttube, Rijke” tube tube), Helmholtz resonance box and lean pulse pot (Rey nstpulse pot)), the basic principles that control their operation are the same. Add energy periodically in the same phase as the periodic pressure vibration. (Rayleigh's criteria) erion)) Despite such apparent simplicity, the problems that occur during a pulse combustor The process involved is extremely complex. The process involves highly disordered three-dimensional non- Contains a steady flow field (transient rlov rield) and fluctuates It has the physical properties of They are furthermore resonant pressure groups (resonant pr essure field) and large unsteady energy release (energy re lease), and its characteristic time (characterisHc　U ses) is on the same order of magnitude as the solidification time for chemical reactions and fluid dynamic mixing. 5allIeorder of magnNude). Even more burning All aspects of the baking system are highly interconnected.

Pulse combustor operating conditions through various specific time impulses (iIIpact) There are many factors that can influence. For example, combustion characteristics, turn Dunn ratio, heat transrer and equilibrium ratio ence ratios) have an important influence on the behavior of the pulse combustor. give.

However, for pulsed combustor behavior, the time scale of fluid dynamic mixing It can be seen that (scale, ratio) has a very strong influence. various related Since all time scales can be compared, and the fluid dynamic mixing time scale Since kale is controllable, fluid dynamic mixing is only necessary to achieve the desired operating conditions. rather, it can be used to compensate for variations on other time scales.

Summary of the invention One of the objects of the present invention is to control the injection of combustion reactants into the combustion chamber so that the pulsed combustion By providing a method and apparatus for controlling the combustion characteristics of a burner, The aim is to eliminate potential drawbacks in the Luss combustor.

Another object of the invention is to displace the flow of new reactants with the hot combustion products of the previous cycle. Method and apparatus for controlling combustion processes by controlling body dynamic mixing characteristics The goal is to provide the following. Such control should be done using appropriate feedback mechanisms. It may be dynamic or static.

To achieve those and other objects, the present invention provides that the combustion products are a combustion chamber, an outlet mechanism for discharging combustion products from the combustion chamber, and a combustion chamber within the combustion chamber; Combustion reactants are controlled at a predetermined velocity and mass flow rate (mas s "low rate" inlet geometry (inle Combustion in a pulse combustor with population mechanism with t geolletry METHODS AND APPARATUS FOR CONTROLLING CHARACTERISTICS. The method and apparatus of the present invention utilize combustion reaction The mixing properties of matter and combustion products can be expressed as a function of population geometry (runcti). on). The term used here is “as a function (as a run ction of) J terms are defined as the chosen population geometry and the resulting combustion Refers to the relationship or association of influences on the mixing characteristics of reactants and combustion products.

Other embodiments of the invention relate to the following improvements in pulse combustors. Sunawa (1) Extending the turn-down ratio of the pulse combustor method and apparatus; (2) energy release rate to obtain desired pulse combustor operation; How to adapt the temporary position (tcvporal 1 location) and and (3) a method and apparatus for compensating for the effects of fuel composition. Each Embodiments of the invention employ special inlet geometries to achieve the desired fluid dynamic mixing. Ru. The inlet geometry may be fixed or variable. Modify the geometry to yield fluid dynamic mixing time scales (modi fy) that brings about a change in the characteristics of fluid dynamic mixing. It is. In a preferred embodiment, the invention provides a static or dynamic It can also be used in Static applications of the invention include the manufacture of pulse combustors. or during field maintenance, so that the desired operating conditions are achieved. This is achieved by modifying the injection geometry to change the fluid dynamic mixing properties.

The dynamic application of the invention is based on appropriate system parameters (e.g. combustion chamber pressure, desired operating conditions are achieved while monitoring control the geometry of the injection through appropriate feedback loops so that This is achieved by changing the fluid dynamic mixing characteristics.

Below, influence the fluid dynamic mixing characteristics to achieve the desired pulsed combustion behavior. Describe some of the geometries that can be used. Their geometry is exhaustive but rather an example of how to change fluid dynamic mixing properties. It is nothing more than

Brief description of the drawing The present invention will now be described with reference to the accompanying drawings.

FIG. 1 is a theoretical explanatory diagram of a pulse combustion configuration.

Figure 2 shows a theoretical prediction of the effect of mass flow rate on mixing time in a pulse combustor. It is a thought graph.

Figure 3 shows experimental results showing the effect of mass flow rate on energy release in a pulse combustor. This is a graph of the results.

FIG. 4 shows a pulse combustor incorporating features of the present invention. FIG.

Figure 5 shows an outline of the geometric shape of a multiple jet (Note 5) person according to an embodiment of the present invention. FIG.

FIG. 6 shows a plurality of nozzles having injection nozzles of different radii according to a second embodiment of the present invention. FIG. 3 is a schematic illustration of the injection geometry.

Figure 7 shows the mixture ratio in a pulse combustor with multiple nozzles of different radii shown in Figure 6. It is a schematic explanatory diagram showing (mtxing rate).

FIG. 8 is a schematic explanatory diagram of an injection system according to a third embodiment of the present invention.

Figures 9a and 9b illustrate the present invention that utilizes variable artificial geometry to control fluid dynamic mixing. Two embodiments of the invention are illustrated.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS An inherent characteristic of most pulse combustors is that the new combustion products of the previous cycle This is the fluid dynamic mixing of new reactants. Various forms with mainly different mixing properties The test results of the con ``iguratton'' show that fluid dynamic mixing is It is known to be important for the operation of russ combustors.

However, until recently, the precise role of mixing has not been quantified either empirically or theoretically. There wasn't. In order to quantitatively understand the characteristics of fluid dynamic mixing in a pulse combustor, Fig. Geometric characteristics that define critical system operation and fluid dynamic mixing times, such as A theoretical model has been developed that equates the

Referring to FIG. 1, combustion chamber 10 has an inlet 12 and an outlet 14. Fuel at temperature T and combustion reactants such as air R1' The loading of the combustion chamber 1 containing the combustion products P of the previous combustion cycle at a temperature T 0 from the inlet 12. The entrance 12 is circular. may also be noncircular, but a circular shape with a radius of An orifice or jet hole is preferred, with a direction of mass flow rate of the combustion reactants and a continuous The injection rate of the combustion reactant (determined from the equation) is U. The mixture ratio is determined by the combustion reaction. The substance R1 is mixed with the combustion product P at the temperature Tp and reaches the ignition temperature T. X This is a high rate. For methane, T is about +11! 1.500 and after about 1 ms (i.e. 1. ms chemical ignition delay time) It is the temperature at which ignition occurs and therefore energy release occurs. Therefore, the mixing ratio is It is a measure of the energy release rate. For other combustions, different The value of D, and the chemical ignition delay are required. Chemical Compassion 1x Ignition delay is the time from when the reactants reach temperature ``IIX'' to when a rapid reaction begins. This is due to the delay. The mixing time is from the point of introduction of one element of the reactants into the combustion chamber. It is the time until the reactants reach the temperature T.

IIX Figure 2 shows some typical theoretical results.

As shown, the mass flow direction of the reactants has a dramatic effect on the mixing characteristics of the reactants. have Mass flow alone limits the range of combustion action and is function over a wide range of energy release rates, and thus achieve the desired turn dunnage ratio. It has been found that this is impossible. Theory also suggests that the initial slot of the mixing ratio Both the loop and peak mixing ratios are expected to decrease with decreasing mass flow rate. There is. These effects have been experimentally proven as demonstrated by the results shown in Figure 3. ing. The theoretical results shown in Figure 2 are for a single inlet and are shown in Figure 3. It should be noted that the experimental results are for multiple inlets that influence each other. be. However, the results shown in FIG. 3 support the theoretical predictions shown in FIG.

A book on controlling the mixing properties of combustion reactants and combustion products as a function of population geometry. The method and apparatus of the invention is schematically illustrated in the pulse combustor of FIG. Burning The firing chamber 20 has an inlet 22, an outlet 24 and an initial charge of reactant R1 for igniting. A spark plug 26 is provided. The reactants are preferably placed upstream of the inlet 22. It consists of air from the blower 28 and fuel from the fuel supply port 30. Air is in air After passing through the inlet valve 32, the fuel is dispersed through the fuel inlet valve 34, and the air and fuel are separated. are mixed in the mixing chamber 36. However, the present invention does not require premixed reactants or unmixed reactants. It is applicable to any system employing a mixture of reactants.

Reactant R1 passes through a port 22 with a fixed or adjustable inlet geometry. It enters the combustion chamber 20. The inlet 22 of FIG. 4 has a variable population geometry and a movable central body. 38 can change the inlet geometry of the inlet 22, thereby increasing the inlet geometry within the combustion chamber 20. The fluid dynamic mixing characteristics of combustion reactant R1 and product P are adjusted. Movable central body 38 via a link 40, preferably located upstream of the air population valve 32. It is moved by a tuator 42.

When dynamic or feedback control is applied, the actuator 42 by a microprocessor 44 that receives signals from a sensor 46 within the baking chamber 20; controlled. Sensors include pressure, periodic and/or chemiluminescence. to monitor the actual combustion characteristics of and compare those signals with the desired combustion characteristics. is returned to the microprocessor 44 through a feedback loop 48. desired flame Deviations between the combustion characteristics and the actual combustion characteristics result in selective actuation of actuator 42. of the inlet 22 (by movement of the central body 38 relative to the inlet 22) changing the inlet geometry and thereby changing the mixing characteristics of combustion reactant R1 and product P; , resulting in changes in combustion characteristics.

In a preferred embodiment of the invention described above, the inventive concept is applied to a pulse combustor turbine. It is used in the control mechanism to adjust the damping ratio. In Figures 2 and 3, The mixing time is determined by the ratio of the inlet orifice radius to the injection rate, i.e. r/u. Therefore, it is measured or converted (scaleswlth ratio r / u ), the conversion is as illustrated by the first upward curve in Figures 2 and 3. , it is almost straight. Therefore, r/u is maintained constant and O Vine injection systems that vary the mass flow direction of reactants have a wide range of turn-on ratios resulting in a constant mixing characteristic over time. of such mass flow rate One method and apparatus for achieving the change is to change the fixed injection geometry shown in FIG. I am using it. In Figure 5, six independent pour orifices or spouts ( jet) is shown, but more or less than that may be used. Close The open nozzle 50 is indicated by a black circle, and the open nozzle 52 is indicated by an open circle. It shows. Each nozzle has a fixed radius r, and therefore a fixed radius What shape does it have?

Closing individual orifices sequentially as the mass flow rate decreases1. The injection rate ( u) can be kept constant. In the same way, the mass flow rate increases. Thus, individual spouts are opened. Since the radius of the nozzle (r) is fixed, the ratio r/u is constant, and whether it is a mixed property or unchanging O It is certain that As mentioned above with respect to FIG. 4, the measurement of the pressure no. and open or close several spouts depending on the determined pressure. A suitable feedback system working with each individual orifice to provide a mechanism to control A stem is used. Other applicable control measures determine the period of the combustion cycle. How to monitor the characteristics of combustion process signals such as Feedback in combination with a chemiluminescence measurement system that precisely determines the time This includes the lock system.

Other embodiments of the invention provide a temporary energy release rate (tempo) in a pulse combustor. ral energy release rates) be. The strongest and most stable operation of a pulse combustor is due to its energy resolution. The emissivity is a resonant acoustic pressure field. in the same phase as e　eld) and at its peak. arise. Since the energy release rate is a function of the mixing characteristics, the energy release rate can be varied can be adjusted by selecting the geometry of the injection orifice. this theory is based on the discovery that the mixing time is a function of the ratio r/u.

A schematic representation of the geometric shapes that can be adopted to adjust the energy release rate is shown in Figure 6. It is. Flow through all orifices A1B, C, D starts at the same time. Each The nozzles (A, B, C, D) have different radii ('Of, r　, r　, r　, respectively) have. While the injection speed of each nozzle is the same, r/u changes. Therefore, it is possible to change a=waiting time of each nozzle. Is it the mixing time? This is because it is determined by /u (scales with r /u).

By selecting the radius of each individual orifice and adding the mixing ratios of all the orifices, the figure Any desired temporal mixing contour (temporal mlxingprole) or characteristics can be changed. Room pressure, cycle period or through the use of chemiluminescence measurements, as discussed with reference to Figure 4. For almost all pulse combustion devices using feedback loops such as However, the optimal blend profile can be tailored.

Other embodiments of the invention provide improvements associated with changes in fuel properties in a pulse combustor. It is about accounting (accounting f’orvartaNons). Ru. The properties of the fuel affect the behavior of the pulse combustor. For example, do not premix In a Helmholtz-type pulse combustor operating in low mode, 20a+s Apart from the system acoustic time scale, the chemical mechanical time scale The change in lis in the fuel (achieved by changing the chemistry of the fuel) ), leading to dramatic effects on system behavior. In particular, the theoretical model and a fixed mass flow rate of air (at a constant "iring rate") For operation), we predict that the mixing time is proportional to (3). Either embodiment can be used to compensate for changes in fuel properties. " Small changes in can also be used to compensate for these changes.

One possible physical configuration for achieving compensation for such chemical composition effects is shown in Fig. 8. FIG. 8 shows that the injection orifice 60 has an adjustable aperture (fri). s) variable geometry va with variable radius r obtained by using I " shows an injection system having a The variable radius r of the injection orifice 60 is Compensating for changes in the properties of t4 It's coming. Therefore, some change in U will change r o O This can be compensated for by keeping r/u constant. Fi　O - the release control means may include room pressure, cycle period or may be provided to adjust r depending on the chemiluminescence determination of the reaction. can.

In two other embodiments of the invention (FIGS. 9a and 9b), the injection orifice is Refice and variable valve system that can change the fluid dynamic mixing characteristics of the combustor It is composed of In the one shown in Figure 9a, the combustion characteristics are monitored. In response to feedback loop 1.20, the stagnation plate valve ion plate valve) 110, a motor-driven Actuator 100 is used. The stagnation plate valve 140 is a fuel/air The inlet geometry of inlet 125 is varied to thereby increase the flow of premixed fuel/air reactants. The mixing characteristics with the combustion products in the combustion chamber 105 are adjusted. Preferably, the feedback A microprocessor for monitoring the drive signal and operating the actuator 100. A processor 30 is adopted. The desired pressure oscillation in the combustor is thus maintained. Ru. Other system characteristics monitored and used to control fluid dynamic mixing are the combustion period and chemiluminescence.

Any variable valve geometry that can change the fluid dynamic mixing characteristics of the combustor may be employed. It can be done. Figure 9b shows a conical shaped plate that acts the same as the variable stagnation plate shown in Figure 8a. The same embodiment as shown in FIG. 9a is illustrated, except that a filler plate 140 is used. Individual Various stagnation shapes can be created by changing the inlet geometry to accommodate different pulse combustors. It can be used to obtain desired mixing characteristics.

A detailed description of the invention has been provided along with several examples. But based on those disclosures Those skilled in the art will be able to make modifications and improvements to the present invention, which are disclosed in the following claims. still within the scope and spirit of the invention as defined.

Time (seconds) FIG. 2 Normalization time (1/1 cycle) FIG.3 Dimensionless time (↑/↑cycle) FIG.7

Claims (40)

[Claims] 1. a combustion chamber in which the combustion products are located; and a combustion chamber for removing the combustion products from the combustion chamber. a predetermined velocity within the combustion chamber for mixing with the outlet and the combustion products within the combustion chamber. Inlet hand with inlet geometry for introducing combustion reactants at A method for controlling combustion characteristics in a pulse combustor consisting of stages, the method comprising: A method for controlling the mixing of substances and products of combustion as a function of the inlet geometry of said inlet means. A control method with a certain degree of control. 2. controlling the mixing characteristics as a function of the inlet geometry; A process for fixing and controlling the mixing properties as a function of the fixed inlet geometry. 2. The method of claim 1, comprising the steps of: 3. controlling the mixing characteristics as a function of the inlet geometry; process and control the mixing properties as a function of its variable inlet geometry. 2. The method of claim 1, further comprising the steps of: 4. Claim 1: The step of controlling the mixing characteristics comprises the step of controlling the mixing time. Method described. 5. a step of detecting combustion characteristics within the combustion chamber, and depending on the detected combustion characteristics; The inlet geometry is adjusted to obtain the desired mixing characteristics necessary to achieve the desired combustion characteristics. What process of changing shape 2. The method of claim 1, further comprising: 6. A claim in which the step of detecting the combustion characteristics includes detecting pressure within the combustion chamber. The method described in Section 5. 7. The step of detecting the combustion characteristics includes detecting a cycle of combustion within the combustion chamber. The method according to claim 5. 8. The step of detecting combustion characteristics includes detecting chemiluminescence. The method according to claim 5. 9. said inlet means has at least one orifice having a radius; The process of controlling the mixing characteristics of the radius of the orifice relative to the velocity of the combustion reactants 2. The method of claim 1, comprising controlling mixing characteristics as a function of ratio. 10. The step of controlling the mixing characteristics as a function of the radius/velocity ratio includes: 10. The method of claim 9, comprising the step of controlling the mixing time as a function of the ratio of . 11. 11. The method of claim 10, wherein the mixing time varies linearly with the radius/velocity ratio. . 12. The process of controlling the mixing characteristics is constant over a wide range of turn dunnage ratios. The mass flow rate of the combustion reactants is varied to obtain the mixing characteristics of the radius/velocity ratio. 12. The method according to claim 11, further comprising the step of maintaining constant. 13. at least one orifice of said inlet means has equal radii; a plurality of orifices that are selectively closed to obtain the certain mixing characteristics. selectively controlling a portion of the plurality of inlet orifices to close and maintain a constant velocity, thereby keeping the radius/velocity ratio constant and maintaining a constant velocity. 13. The method according to claim 12, wherein mixed properties are obtained. 14. at least one orifice of said inlet means has unequal radii a plurality of orifices, and the step of controlling the mixing characteristics produces a desired mixing profile. Combustion reactants flowing through each orifice, preferably of a plurality of orifices. The mixing time of each nozzle is varied by equalizing the speed of the 12. The method according to claim 11. 15. the at least one orifice comprises a variable radius orifice; The step of controlling the mixing time selectively varies the radius of the orifice while Keep the flow rate constant and vary the mixing time as a function of the selected radius, and 11. The method of claim 10, further compensating for changes in properties of combustion reactants. 16. 16. The mixing time varies with respect to the cube of the selected radius. the method of. 17. the inlet means comprising a valve and a flow restrictor through the valve; The step of changing the inlet geometry changes the relative position of the valve and the flow restrictor of the valve. The method according to claim 1, wherein the opening degree of the valve is changed by changing the position of the valve. . 18. 18. The method of claim 17, wherein the flow restrictor is a movable splash plate. Law. 19. 18. The method of claim 17, wherein the flow restrictor is a movable cone. 20. The process of detecting combustion characteristics in the combustion chamber, and depending on the detected combustion characteristics, flow restrictors to obtain the desired mixing characteristics needed to achieve the desired combustion characteristics. 18. The method according to claim 17, further comprising the step of changing the relative position between the valve and the valve. Law. 21. a combustion chamber in which the combustion products are located, and for removing the combustion products from the combustion chamber; a predetermined amount within the combustion chamber for mixing with the combustion products within the combustion chamber. Inlet with inlet geometry for introducing combustion reactants at velocity and mass flow rate A device for controlling combustion characteristics in a pulse combustor comprising means for controlling combustion reaction. controlling the mixing of reactive substances and combustion products as a function of the inlet geometry of said inlet means; A device having means. 22. The means for controlling mixing characteristics as a function of said inlet geometry and controlling the mixing properties as a function of the fixed inlet geometry. 22. The apparatus of claim 21, comprising means. 23. The means for controlling mixing characteristics as a function of said inlet geometry and controlling the mixing properties as a function of its variable inlet geometry. 22. The apparatus of claim 21, comprising means. 24. Claim: wherein the means for controlling the mixing characteristics comprises means for controlling the mixing time. 22. The device according to 21. 25. means for detecting combustion characteristics within the combustion chamber, and depending on the detected combustion characteristics; , said inlet to obtain the desired mixing characteristics necessary to achieve the desired combustion characteristics. Means of changing geometry 22. The apparatus of claim 21, further comprising: 26. The means for detecting the combustion characteristics may include means for detecting pressure within the combustion chamber. 26. The device according to claim 25. 27. The means for detecting combustion characteristics includes means for detecting a cycle of combustion within the combustion chamber. 26. The apparatus of claim 25, comprising: 28. The means for detecting combustion characteristics comprises means for detecting chemiluminescence. 26. The method of claim 25, comprising: 29. said inlet means has at least one orifice threatening a radius; The means for controlling the mixing characteristics is the radius of the orifice relative to the velocity of the combustion reactants. 22. The apparatus of claim 21, including means for controlling the mixing characteristics as a function of the ratio of the mixing characteristics. 30. The means for controlling the mixing characteristics as a function of the radius/velocity ratio includes: 30. The apparatus of claim 29, further comprising means for controlling the mixing time as a function of the ratio of . 31. 31. The mixing time varies linearly with radius/velocity ratio. equipment. 32. The means for controlling the mixing characteristics is constant over a wide range of turn dunnage ratios. The mass flow rate of the combustion reactants is varied to obtain the mixing characteristics of the radius/velocity ratio. 32. Apparatus according to claim 31, comprising means for maintaining constant. 33. at least one orifice of said inlet means has equal radii; a plurality of orifices that are selectively closed to obtain the certain mixing characteristics. means for selectively controlling a portion of the plurality of inlet orifices to close and maintain a constant velocity, thereby keeping the radius/velocity ratio constant and maintaining a constant velocity. 33. Apparatus according to claim 32, comprising means for obtaining mixed properties. 34. at least one orifice of said inlet means has unequal radii a plurality of orifices, and the means for controlling said mixing characteristics is configured to provide a desired mixing profile. Combustion reactants flowing through each orifice, preferably of a plurality of orifices. have a means of varying the mixing time of each nozzle by equalizing the speed of the 32. The apparatus of claim 31. 35. the at least one orifice has a variable radius, and the mixing time means for controlling the mass flow rate while selectively varying the radius of the orifice. and have means for varying the mixing time as a function of the selected radius, and 31. The apparatus of claim 30, further compensating for changes in properties of combustion reactants. 36. 36. The mixing time varies with respect to the cube of the selected radius. equipment. 37. the inlet means comprising pulp and a flow restrictor through the valve; The means for changing the inlet geometry changes the relative position of the valve and the flow restrictor of the valve. 22. The device according to claim 21, wherein the opening degree of the valve is changed by changing the position of the valve. Place. 38. 38. The apparatus of claim 37, wherein the flow restrictor is a movable splash plate. Place. 39. 38. The apparatus of claim 37, wherein the flow restrictor is a movable cone. 40. means for detecting combustion characteristics within the combustion chamber, and depending on the detected combustion characteristics; flow restrictors to obtain the desired mixing characteristics needed to achieve the desired combustion characteristics. 38. The apparatus of claim 37, further comprising means for changing the relative positions of the valve and the valve. Place.