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Techniques recently developed for solving sparse sets of equations are applied to the linear atom-balance and generally nonlinear mass-action relations of gaseous reaction equilibria. A convergence criterion for choosing the component basis is derived. A new ′tearing′ algorithm which takes advantage of small subsets of equations that can be solved directly is shown to be useful in reducing the number of compositions which must be guessed and iterated. In some cases spectacular reductions can be found, as illustrated by solution procedures derived for a hydrocarbon combustion system and a volcanic gas system. In the former a potential improvement on the already impressive Carter—Altman scheme is uncovered.

Pressure fluctuations have been recorded at various points in the ducting of a jet engine. The recordings were made under a variety of steady running and accelerating conditions with a standard engine and with engines adapted for two different after-burning systems. This report includes a brief description of the recording equipment and its method of use, a summary of the test conditions, a description and analysis of the pressure records obtained and a discussion of the test results. In the discussion an attempt is made to explain the observed pressure fluctuations, and their significance in relation to practical engine operation and combustion system design is stressed.

A carbon dioxide collection accessory is described for the previously reported combustion system for preparation of biological samples for liquid scintillation counting. A sample can be burned and collected every 3 min. Sample size is limited by the capacity of the solvent to absorb carbon dioxide without precipitation. The system can be used for collecting water as well as carbon dioxide, for double isotope counting. The method has a collection recovery of 97%, is calibrated by internal standards, and shows a coefficient of variation of 1.1%.

有機元素分析用燃焼装置の小型化について検討を行なった.その結果,すでに報告してある内管方式の燃焼管を改良し燃焼管の直径を2.2cmと太くし,管内を二重にして,内側で気化分解した試料ガスを外側の酸化剤層で完全に燃焼させるような新しい燃焼管を考案することにより,燃焼管の長さを従来のそれの約1/3に短縮することができ,また,電気炉も従来の試料焼却炉,燃焼炉,銀線加熱炉の3炉が,約20cmの長さの燃焼炉のみでじゅうぶんとなった.本装置は重量法による元素分析装置に構成できるのみならず,光電比色計と連結することにより,有機物水溶液の炭素分析も迅速に行なうことができる.

Experiments on enclosed laminar diffusion flames have revealed the existence of a critical relative velocity of air and fuel which is associated with the threshold of low frequency flame vibration. Starting from the hypothesis that these vibrations are triggered by a selectively amplified disturbance arising in the free shear layers near the base of the flame, the authors have obtained evidence of the nature of the disturbance. Further systematic experiments have enabled them to account for the observed behavior of low frequency vibrating diffusion flames in the light of their hypothesis and in relation to the acoustical properties of their combustion system. Dea experiences faitea sur dee flammes a diffuaiun laminaim close ont revele I'existence d'une vitesae relative et critique de I'air et du combustible, laquelle ttait aesociic au seuil d'une vibration a faiblr frdquence de la flamme. En partant de I'hypothkse que ccs vibrations sont dhclcnchdes par une perturbation amplifide d'une maniire sblcc- tive qui se developpe dans lea couches libres de cisaillement pris de la base de la flamme, les auteurs ont obtenu dea preuves de la nuture de la perturbation. D'autres expPri- enccs systdmatiques ont permis aux auteurs d'expliquer le comportement observe de flammes i diffusion vibrant a faible frhquence, a la lumiere de leur hypothese et par rapport aux propribtha acoustiques de leur systeme dr combustion.

An alcohol combustion system incorporating an all-metal burner and automatic ignition system has been devised. With this apparatus it is possible to convert about 2 L of alcohol per day into pure water.

The Texaco Controlled-Combustion System, a stratified charge concept utilizing a coordinated arrangement of air swirl, fuel injection and positive ignition, has been shown over many years of development in numerous engine conversions to produce excellent fuel economy, inherently low exhaust emissions and the ability to prevent combustion knock without regard to fuel octane or cetane number. Recent work has demonstrated the capability of the system to meet the very stringent emission levels of the 1976 U.S. Federal Standards for light duty vehicles and the potential to maintain these levels during 50,000 miles of testing.

Workers in the field of continuous combustion have long been aware of the importance of the part played by the aerodynamic factors in the satisfactory operation of combustion systems. Although only part of a complex process, the air flow in a combustion system can, to some extent, be studied as an isolated individual factor, without the complications of fuel injection and heat release. This may appear to involve a rather long step from reality, but observations of the basic “cold” flow conditions in such a system can provide a valuable basis for the prediction of the effects of variations in the equipment, particularly in systems conforming to a particular type.

Swirl, or rotation of the air charge, is increasingly popular as an aid to fuel distribution in Diesel engines, but as yet little is on record as to the principles of its production and use. On certain types of engine it is possible to mount a “swirl meter” or freely rotating vane within the combustion chamber, and thus by motoring the engine to obtain a measure of the swirl rate. From such experiments and from theoretical considerations, one can draw certain conclusions, and although these are directly established only as regards one particular combustion system, indirect evidence suggests that they have a much wider application. The most important conclusion is this, that with the combustion system in question there is an optimum “swirl ratio,” or number of revolutions of the vane per minute divided by the number of revolutions of the engine per minute which gives the best performance, whatever the engine size, speed, or load, and which is, in fact, characteristic of that combustion system. It seems probable that the same rule applies to other swirl systems. In most cases the “swirl ratio“ is roughly constant over a wide speed range. This means that if this ratio is made correct at one speed, it will not be far wrong at any speed within the working range, a fact which accounts for the popularity of swirl type engines in vehicle and other variable-speed services. The primary effect of swirl is that of winnowing the fuel spray, blowing away fine spray and burnt gas, and giving the heavier particles access to fresh air. There are, however, important secondary effects of which the causes are not known with certainty.

A new simplified technique for gas assays of tritium is described. The method is based on the combustion of the labelled compound and on the indirect conversion of the combustion water to ethane. Combustion and conversion are carried out according to procedures used for the purpose of microanalysis of organic substances, by means of a combustion system with built-in tube fillings. No vacuum system is needed for the assays. The method furnishes quantitative activity yields and reduces the possibility of isotope fractionation.

Author Institution: Atmospheric Chemistry and Combustion System Division, Battelle Memorial Institute

A new approach is reported for the gas-liquid radiochromatography of 14C-containing compounds. The column effluent is split between a mass detector and a combustion system, and the [14C]carbon dioxide arising from the individual chromatographic components is trapped in vials containing Hyamine. Each vial is then subjected to conventional radioassay by liquid scintillation counting. Applications of this approach to biosynthesis and drug metabolism problems are presented.

A Description of the Development of the Bristol Siddeley Pegasus and Plenum Chamber Burning for the BS.100 and an Outline of the Performance of a V/S.T.O.L Subsonic Strike Fighter Utilizing a Vectored Thrust Engine with PCB as Compared with a Composite Power Plant Fighter and a Vectored Thrust Type without PCB. The Bristol Siddeley Pegasus vectored‐thrust turbo‐Tan has now been in operation for six years, and during that time has been developed to a fully operational stan‐dard in the Hawker Siddeley Kestrel V/S.T.O.L. sub‐sonic strike fighter. Initial development of a second‐generation V/ S.T.O.L. strike fighter for supersonic flight necessitated thrust augmentation by combustion in the normally cold by‐pass flow. This gave rise to the design and development of a suitable combustion system, now known as ‘Plenum Chamber Burning’, or ‘PCB’. This paper summarizes the satisfactory development of the Pegasus vectored‐thrust turbofan, gives some description of the PCB system development, and shows how the application of this system to a V/S.T.O.L. subsonic strike fighter vectored‐thrust power plant gives the latter considerable superiority when compared with an equivalent composite power plant configuration.

The gas turbine has created new workshop problems arising from the use of special materials and from the complexity of some of its component parts. The construction of experimental sets calls for much improvisation to avoid heavy expenditure on special tools and machines, and the paper gives examples of methods which meet this requirement. Blading for axial turbines and compressors when required only in small numbers, as in the manufacture of experimental sets, is probably the major problem and cannot be met without the provision of some special facilities, the basis of which is usually copy machining. One of the most notable developments has been the use of sheet metal in the gas turbine, not only for the combustion system but also for structural parts, many of which are subject to severe conditions imposed by high temperatures, and fatigue stressing. The highest grade workmanship is essential in this connexion, to ensure reasonable life, free from failure. The special demands of gas-turbine design are constantly giving rise to new manufacturing techniques and the paper deals briefly with some of these, such as those associated with welded rotors and precision forged blading.

This paper concentrates on the combustion experience gained by the application of the Rolls-Royce Avon aero gas turbine to industrial usage and each of the following subjects is considered in detail. A brief summary of the design philosophy which has dictated the configuration of the basic aero combustion equipment. The particular implications of industrial operation as this affects the combustion system. This includes the effect of different fuels and operation for long periods in a ground level environment. The operational problems experienced to date with the basic aero equipment and the design and development work undertaken to overcome them. These problems comprise frettage, flare distortion, smoke output, starting, corrosion and combustion stability. The design and development of an improved system, now under way, which will be capable of satisfactory operation with a wide range of liquid or gaseous fuels without component change. The use of steam injection into the combustion system as a means of improving overall cycle efficiency. Consideration of the range of industrial fuels available, from diluted gases to distillate and residual oils, and their suitability for gas turbine usage. Future trends in combustion technology.

C and evaporation may be included among the more difficult problems encountered by an engineer or chemist in, for example, the design of a wind tunnel or a propulsion system. These heterogeneous processes involve a number of phenomena, and it is quite difficult to predict on theoretical grounds which of these phenomena will be important in a particular case. It is even more difficult to investigate these processes experimentally. This article describes recent work on condensation and evaporation which is applicable to propulsion and high speed flow but includes other work in order to provide insight into these problems. The bibliography is, of course, only indicative of the voluminous literature on these subjects, although information directly relevant to propulsion and flow is very limited. Condensation was recently reviewed by Steve r (l) and others (2-4). Evaporation was recently reviewed by Knacke and Stranski (5).

Rates of carbon monoxide oxidation in after-flame gases at 1 atm were determined by concentrationand temperature measurements, both in a differential flow reactor comprising the second stage of a two-stage city gas-air combustion system, and in the postflame region of a flat methane-air flame stabilized on a water-cooled burner. Rates observed in the flow reactor at 1060°–1260°K are about 1×10−5 to 4×10−5 mole/ml, sec, corresponding to, a rate of fractional conversion, -d ln[CO]/dt, of about 0.05 to 0.2 msec−1. The flat-flame rates decrease rapidly with distance from the burner, in a manner consistent with a kinetic mechanism based on rate control by the forward and reverse steps of the reaction CO+OH=CO2+H, equilibration of the reactions H+O2=OH+O, O+H2=OH+H, OH+H2=H2O+H, and three-body recombinations, if the partial-equilibrium OH concentration is corrected by a factor ranging from 0.39 to 2.62. The above results and previous data representing various burners and reactors, fuels, equivalence ratios, and pressures, are adequately correlated for practical purposes over the temperature range 840°–2360°K by the global equation -d[CO]/dt=k0[CO][O2]1/2[H2O]1/2exp(-E/RT), with k0=1.3×1014 ml/mole sec, and E=30 kcal/mole.

The L9204 FMV engine developed by Maschinenfabrik Augsburg-Nurnberg AG (M.A.N.) is an air-cooled, 4-cyl, in-line unit with remarkable multifuel capabilities. With a displacement of 162 in3, it is rated to produce 70 hp at 3800 rpm. The use of the FM combustion system, in addition to conferring multifuel ability, has made it possible also to achieve a high power/weight ratio. This paper presents details of the engine design and operating data, and results of endurance testing are given.

The AiResearch TPE turboprop engine is a single-shaft gas turbine rated at 605 shp. The combustion system of this engine is described, and the design considerations and development of the combustion system are discussed.Copyright © 1967 by ASME

Some of the problems encountered in combustion-system design are discussed with particular attention to combustor discharge-temperature patterns. The results of extensive laboratory and field tests that culminated in improved temperature patterns are presented.Copyright © 1964 by ASME

The low emission potential of continuous combustion systems has generated considerable interest in their application to vehicular powerplants. While the prime consideration for a vehicular combustion system is low exhaust emissions, emphasis must also be placed on the usual considerations of performance, reliability, durability and simplicity.

Summary A brief explanation is given of the manner in which aircraft performance improvements can be obtained by providing P.C.B. on the high by-pass ratio turbofan engines of subsonic V.T.O.L. aircraft of the Harrier type. The necessity of P.C.B. to supersonic developments is noted. An account is then given of the design considerations behind the choice of the “staggered gutter colander” combustion system for P.C.B., and of the experimental development programme which led, eventually, to the successful demonstration of P.C.B. on an adapted Pegasus engine.

As a result of the requirement that a gas turbine-electric locomotive operate in areas where legislation prohibits operation if the smoke in the exhaust gases exceeds a specified amount, a program was undertaken to develop a combustion system which would meet the requirements without compromising the other performance criteria. This paper describes the physical and chemical nature of smoke, the objective measurement of smoke, the effect of operating variables on smoking tendency, and finally the considerations which led to a combustion-chamber design which met the requirements as evidenced by the engine test results.

This work includes an experimental and modeling study of whether sulfur dioxide (SO2), typically present in the recirculated flue gas, can inhibit or promote the overall fuel conversion process in a combustion system, with special attention on SO2 implication for soot emissions and the possible reduction of this pollutant.