Abstract: A container for collecting water samples to determine dissolved gas includes a flask-type pouch with a spout. A removable cap and valve install on the spout. The valve includes an adapter that fits with an O-ring or other seal inside the mouth of the spout. The valve includes a valve element, which can be a one-way, self-closing type of valve, that fits with an O-ring or other seal inside the end of the adapter. A cap of the container fits over the adapter and affixes to the spout to hold the valve on the spout. In use, the cap can be removed so that the valve element and adapter can be removed for filling the pouch. Otherwise, the cap can remain in place so filling can be performed through the valve element. A tamper-evident ring on the cap may be provided to ensure the integrity of the sample contained in the flask.

Abstract: The present invention provides novel packaging articles, e.g., food and beverage cans. Preferred cans typically comprise a body portion and an end portion, wherein at least one of the body and end portions are aluminum and are coated on at least one major surface with a coating composition of the present invention. Suitable coating compositions of the present invention comprise: one or more polyester resins, wherein at least one of the polyester resins has a glass transition temperature (“Tg”) less than about 50° C., and wherein the polyester resin is formed by the reaction of one or more polyacid molecules and one or more polyol molecules; and a crosslinker. Preferred compositions are substantially free of mobile BPA and aromatic glycidyl ether compounds, e.g., BADGE, BFDGE and epoxy novalacs (e.g., NOGE) and more preferred compositions are also substantially free of bound BPA and aromatic glycidyl ether compounds. In more preferred embodiments (e.g.

Abstract: An apparatus for producing plastic containers includes: a forming machine for producing plastic preforms; a blow-moulding machine for blowing the preforms to obtain containers, provided with a blow-moulding carousel having a plurality of blow-moulding moulds that expand the preforms to obtain the containers; a thermal conditioning station interposed between the forming machine and the blow-moulding machine; a storage station, configured for receiving and containing preforms; a supplying system for feeding the thermal conditioning station with preforms contained in the storage station.

Abstract: A saddle sling for supporting a saddle against a vertical support such as a fence post includes a hook (e.g., C-, V-, U- or L-shaped hook) configured to engage a cantle or pommel edge of a saddle (i.e., an equestrian saddle). The hook defines a gap into which the engaged edge of the saddle is received. A tether loop extends from the hook. The loop is sufficiently long to extend from the engaged edge past the opposite edge and over a vertical support, such as a fence post or picket. The loop may be fixed, adjustable or retractable. The saddle is thus held between the hook and the fence or fence post.

Abstract: A duplex fluid filter assembly allows extended life between filter replacements, by automatically back-flushing one filter unit with clean fluid from another filter unit of the duplex assembly.

Abstract: A filter arrangement includes a media construction comprising a corrugated sheet secured to a flat sheet rolled into a coiled construction. A frame and a first seal member are provided. The frame secures the first seal member to the coiled construction. The first seal member is preferably oriented to form a radial seal with a housing. A second seal member is secured to the outer annular surface of the coiled construction. The second seal member includes a gasket extension having first and second opposite ends; an attachment portion; and a protrusion extending from the attachment portion. The second seal member is preferably oriented to form an axial seal with a housing. Air cleaners preferably utilizing filter arrangements as described herein operably installed within housings. Methods of installing, filtering, assembling, and servicing preferably include arrangements as described herein.

Abstract: A separating element for separating liquid from a gas flow is arranged in a separating container of a liquid separator. The separating container has a housing with a container opening and a cover closing off the container opening. The sealing element has a collar arranged between housing and cover and supported on an upper area of the housing facing the cover. A sealing element is provided that has sealing surfaces arranged between the upper area of the housing and the cover such that the separating container is sealed relative to ambient pressure. The sealing element has a holding element monolithically formed with the sealing element and captively securing the sealing element on the collar. The sealing surfaces and the holding element are designed such that a function of sealing the separating container and a function of holding the sealing element on the collar are separate from each other.

Abstract: The present disclosure relates to porous ceramic articles and a method of making the same. The porous ceramic articles have microstructure of sinter bonded or reaction bonded large pre-reacted particles and pore network structure exhibiting large pore necks. The method of making the porous ceramic articles involves using pre-reacted particles having one or more phases. A plastic ceramic precursor composition is also disclosed. The composition includes a mixture of at least one of dense, porous, or hollow spheroidal pre-reacted particles and a liquid vehicle.

Abstract: An artifact free inert filter medium for collection of organic particles is a fibrous material is developed that can be formed into filters used in ambient and indoor air sampling equipment for subsequent laboratory chemical analysis by one of several thermal optical or thermal analysis methods for the determination of organic carbon (OC), elemental carbon (EC), pyrolysis carbon (PC), and total carbon (TC, sum of OC+EC), carbon fractions determined by thermal or thermal-optical analysis methods (OC1, OC2, OC3, OC4, PC, EC1, EC2, EC3) as well can be analyzed in the laboratory for individual organic species by a range of thermal analysis and or extraction/analysis methods.

Abstract: A combine harvester (10), has driven wheels or tracks (14) for moving the combine harvester; a system for detecting characteristics of crop plants (96) in front of the combine harvester and for calculating an expected mass throughput of the combine harvester from said detected physical characteristics; an electronic control (80), configured to control the ground speed of the combine harvester to maintain a desired mass throughput of the combine harvester in consideration of the expected mass throughput of the combine harvester; and a sensor (86) for detecting a combine harvester parameter that is indicative of an actual mass throughput of the combine harvester; wherein the electronic control is configured to compare an output value of the sensor to a value indicating the expected mass throughput and to use a result of the comparison as feedback to control the speed of the combine harvester.

Abstract: A mounting arrangement for mounting a string trimmer to a host vehicle such as a ride-on mower or garden tractor. Functions provided by the mounting arrangement may include adjustment of height and inclination of the cutting head, and relocating the cutting head relative to the body of the host vehicle. The mounting arrangement may include a bumper for protecting the cutting head, cushioning of the mounting arrangement by springs to protect the cutting head from collisions, and transfer of liquid fuel from the fuel tank of the host vehicle to that of the string trimmer.

Abstract: Embodiments of the present invention relate to powered vehicles (e.g., lawn mowers) and, more particularly, to a control system for use with such a vehicle. In one embodiment, the vehicle includes a power source such as an internal combustion engine and one or more drive control levers incrementally movable between a neutral position and a maximum velocity position. The system may also include a velocity profile control system having an adjustment member that permits altering a ratio between control lever movement and velocity of an associated drive member or wheel. Thus, the system may alter a maximum potential velocity of the vehicle while the drive control lever(s) are positioned in the maximum velocity position without varying an output level of the power source.

Abstract: A system for managing warm season, stoloniferous grass turf comprising removing the upper layer of turf down to but not including the stolons, and allowing the grass to regenerate.

Abstract: A mower blade generally comprised of a rotor which connects to the mower at an attachment point and at least one outer end of the rotor, wherein the outer end or ends of the rotor are heavier than the rotor proximate the attachment point. The added weight to the outer end can be by way of an extension or an end section.

Abstract: An interlocking chain unit includes a stepped rod that determines the positions of case plates in a pair and those of guide plates relative to each other. The stepped rod has a small-diameter part that passes through passage holes of the guide plates respectively. The stepped rod has opposite end portions fitting in countersunk holes respectively formed in respective inner surfaces of the case plates. The stepped rod has a large-diameter part with a guide plate side step abutting on a rim of the passage hole of the guide plate, and a case plate side step abutting on a rim of the countersunk hole of the case plate.

Abstract: A gas turbine engine compressed air flow control arrangement, including: a combustion gas structure having an acceleration geometry (20) configured to receive combustion gas (18) from a can combustor and accelerate the combustion gas (18) to a speed appropriate for delivery onto a first row of turbine blades, the combustion gas structure defining a straight combustion flow path; a film cooling hole (58) disposed through the combustion gas structure at a location within or downstream of the acceleration geometry (20); a sleeve (64) surrounding at least a portion of the combustion gas structure comprising the film cooling hole and defining a volume (62) between the combustion gas structure and the sleeve (64); and an adjustable flow control system configured to adjust a flow volume between the plenum (44) and the volume (62).

Abstract: A gas turbine engine includes a compressor for compressing air from an environment; a combustor for receiving the compressed air from the compressor, mixing the compressed air with fuel, and combusting the fuel; a turbine coupled with the compressor for receiving exhaust gas from the combustion and powering the compressor; and an injector coupled with a source of oxidizer for injecting the oxidizer into the combustor. A method for operating a gas turbine engine includes compressing air from an environment; receiving the compressed air at a combustor; mixing the compressed air with fuel; injecting oxidizer into the combustor in addition to the air from the environment; combusting the fuel with the compressed air and the oxidizer; receiving exhaust gas from the combusted fuel; and powering the compression of the air from the environment using the exhaust gas.

Abstract: The invention relates to a device for burning off propellants or explosive substances, which has an activation temperature that lies below the spontaneous ignition temperature of the propellant or explosive substance. The device (1) comprises at least two substances (5, 6) reacting exothermically with one another, wherein at least one first substance (5) is present in a liquid aggregate state below the activation temperature of the device and is separated from at least one second substance (6) by at least one pressure-tight barrier (7).

Abstract: Various embodiments relating to detection of an end-stop position of a waste gate valve and calibration of a waste gate position sensor relative to the detected end-stop position are provided. In this way, it is possible to more accurately control the waste gate.

Abstract: An exhaust system in an engine is provided. The exhaust system includes an exhaust manifold include at least one exhaust runner having an inlet and a flow rotation element including at least one vane, the flow rotation element positioned in the inlet of the exhaust runner swirling exhaust airflow entering the exhaust runner.

Abstract: An exhaust system in an engine is provided. The exhaust system includes an exhaust passage including an outlet, in fluidic communication with at least one combustion chamber in the engine, and integrated into a cylinder head in the engine and a flow rotation element including at least one vane, the flow rotation element positioned in the outlet of the exhaust passage swirling exhaust airflow exiting the exhaust passage.

Abstract: A method for optimizing exhaust backpressure of an internal combustion engine, comprising the following steps: 1) arranging a damping component in an exhaust passage of the internal combustion engine, and allowing an exhaust discharged by the internal combustion engine to pass through the damping component; and 2) allowing the exhaust to be cooled prior to passing through the damping component, or allowing the exhaust to be cooled while passing through the damping component. The method allows for relatively high exhaust backpressure when the internal combustion engine has a low load, and for preventing the exhaust pressure from rising excessively rapid when the internal combustion engine has a heavy load. The apparatus and system for optimizing exhaust backpressure of an internal combustion engine is also provided.

Abstract: A method for operating a dosing apparatus for providing a liquid additive includes providing the dosing apparatus with at least one pump for pumping the additive from a tank into a pressure accumulator, a dosing valve for providing additive present in the pressure accumulator in a dosed manner, and a return valve through which additive present in the pressure accumulator can be led back into the tank. A dosing demand is established, subsequently the pump is activated to build up a pressure in the pressure accumulator, then the pressure in the pressure accumulator is set to a desired metering pressure, and thereafter the liquid additive is dispensed by the dosing valve. A motor vehicle having a dosing apparatus is also provided.

Abstract: A method of estimating an ideal air-fuel ratio in an internal combustion engine, comprises receiving an output of an upstream air-fuel ratio sensor and an output of a downstream air-fuel ratio sensor, the upstream air-fuel ratio sensor being attached to an exhaust gas passage such that it is positioned upstream of a catalyst provided in the exhaust gas passage to purify an exhaust gas, the downstream air-fuel ratio sensor being attached to the exhaust gas passage such that it is positioned downstream of the catalyst; detecting a state in which the catalyst does not store or release oxygen based on the output of the downstream air-fuel ratio sensor; and deciding as an estimated ideal air-fuel ratio in the internal combustion engine an air-fuel ratio detected by the upstream air-fuel ratio sensor when the state in which the catalyst does not store or release oxygen is detected.

Abstract: A unit for recovering thermal energy from exhaust gas of an internal combustion engine including an inlet, an outlet, a heat exchanger arranged downstream of the inlet and upstream of the outlet, and a valve capable of being switched between a recovery position. The exhaust gas flows from the inlet through the heat exchanger to the outlet, and a bypass position, in which the exhaust gas flows from the inlet through a bypass to the outlet. The valve includes separate first and second valve bodies and associated separate first and second valve seats arranged upstream and downstream of the heat exchanger, respectively. The first and second valve bodies are adapted to be switched only simultaneously from the recovery position to the bypass position and vice versa.

Abstract: An internal combustion engine has a cooling jacket at least partially integrated in the cylinder head. The engine has two groups of cylinders: inside cylinders and outside cylinders. Each cylinder has at least one exhaust port, each leading to an individual duct. Individual ducts of outside cylinders converge to form an outside combined duct. In a four-cylinder engine or cylinder head, individual ducts of inside cylinders converge to form an inside combined duct with the inside combined duct remaining separated from the outside combined duct by the cooling jacket. The inside combined duct is farther away from the mounting surface of the cylinder head to the cylinder block than the outside combined duct. The cooling jacket includes upper, middle, and lower cooling jackets and connectors between the upper and lower cooling jackets.

Abstract: A compressed gas energy storage and release (CGESR) system and method. The system has a gas compressor, a container for storing compressed gas, a pressure engine, and an underground high temperature region. Conduits connect the gas compressor, the container and the pressure engine. The compressed gas drives the pressure engine. An electrical power generating means is operatively connected to said pressure engine to generate electricity. The system further comprises a means to heat at least a portion of one of the conduits utilizing heat from the underground high temperature region to heat the compressed gas therein prior to driving the pressure engine.

Abstract: A regeneration circuit includes an oil collection passage that collects return oil from a hydraulic motor to which pressure oil discharged from a hydraulic pump is supplied, a regeneration system that recovers energy from the collected return oil, and an oil resupply passage that resupplies pressure oil from the regeneration system to the hydraulic motor. The regeneration system includes a pressure oil inflow part that converts pressure energy of the collected return oil into mechanical energy, a pressure oil outflow part that outputs low pressure oil with a pressure lower than a pressure of the collected return oil to the oil resupply passage when the pressure energy of the collected return oil is converted into the mechanical energy, and a regeneration part that accumulates the mechanical energy.

Abstract: A pipelayer includes a pilot pressure control unit. The pilot pressure control unit supplies hydraulic fluid to a pilot port of a warm-up control valve so that the warm-up control valve enters an open state when a winch control valve is in the closed state. The pilot pressure control unit drains hydraulic fluid from the pilot port of the warm-up control valve so that the warm-up control valve enters the closed state when the winch control valve is in the open state. The stroke amount from the stroke end of the closed side of the spool of the warm-up control valve when the meter-out opening of the warm-up control valve is fully closed is larger than the stroke amount from the stroke end of the closed side of the spool of the winch control valve when the meter-in opening of the winch control valve is fully closed.

Abstract: An energy system for storing pressurized air and utilizing the pressurized air to generate electricity includes a first storage cavern, a second storage cavern, an air compressor in fluid communication with the first and second storage caverns, an electric generating mechanism, a combustion chamber, a controller and a recuperator. The air compressor is in fluid communication with a compressor piping system, the electric generating mechanism and the combustion chamber are in fluid communication with a generator piping system and the recuperator is in fluid communication with an exhaust piping system and the generator piping system. The controller is configured to operate the energy system such that the compressor directs compressed an into the first storage cavern through the compressor piping system at the same time the electric generating mechanism generates electricity utilizing at least compressed air from the second cavern.

Abstract: A hydraulic hybrid safety system is provided. The hydraulic hybrid safety system is part of a hydraulic hybrid system that has an over-center bent-axis rotary pump/motor with a yoke, the yoke having a zero yoke angle and a plurality of non-zero yoke angles. The safety system includes a spring that is operable to move the yoke to the zero yoke angle when the hydraulic hybrid system loses electrical power.

Abstract: An oil level control device in a main tank of a supply circuit, the supply circuit comprising a main tank, a first pump which, in aspiration, is connected to the main tank, a main hydraulic circuit which is connected in inlet to the delivery of a charge pump and in outlet is connected to the main tank, a first auxiliary conduit, an auxiliary tank which receives oil from the first auxiliary conduit and which in discharge is placed in communication with the main tank. At least a control valve predisposed to control sending of oil from the first auxiliary conduit to the auxiliary tank or from the auxiliary tank to the main tank.

Abstract: A floating eagle type wave power generating device includes an eagle-head-shaped wave absorption floating body, a ship-shaped underwater appendage and a door-shaped support arm. The eagle-head-shaped wave absorption floating body is fixedly connected with an upper end of the door-shaped support arm. A lower end of the door-shaped support arm is connected with first hinges. The first hinges are fixedly connected with the ship-shaped underwater appendage through a base. The door-shaped support arm, together with the eagle-head-shaped wave absorption floating body, can rotate around the first hinges. L-shaped underwater appendages, mounted at two ends of the ship-shaped underwater appendage, are connected with the ship-shaped underwater appendage through second hinges and can rotate around the second hinges. A main floating body is arranged above the ship-shaped underwater appendage and below the eagle-head-shaped wave absorption floating body.

Abstract: A wave-power device comprising a rotatable elongate part comprising axle and a buoyant structure helically coiled around the axle and extending at least part of the length thereof, the rotatable elongate part being connected to a power generator, characterised in that the buoyant structure has a cross-sectional shape having a width greater than its height.

Abstract: A perching mechanism is developed which comprises shape-memory components capable of undergoing motions that render the perching effect. This mechanism can provide unmanned air vehicles with versatile, bird-like landing capabilities on surfaces of different types and orientations.

Abstract: A variable area fan nozzle comprising an array of hinged rigid petals and a petal actuation system in which the principle of actuation is realized by changes in shape (i.e., deformation) of the actuators rather than by movement of cooperating mechanical parts. Because these actuators have no rotating or sliding mechanical components, wear and associated maintenance are reduced. Each deformable actuator has a portion made of shape memory alloy that has been trained to change shape in a specific manner when heated to a temperature above a transition temperature. In addition, each shape memory alloy actuator is shaped to act as a fairing to reduce aerodynamic drag.

Abstract: A hardware retention mechanism comprising a frame including a first guide shoulder and a pivot point; an actuator arm including a first guide post; and a first shape memory alloy wire strung between the first guide shoulder and the first guide post that rotates the actuator arm between a locked position and an unlocked position. The actuator arm is rotatable around the pivot point between a locked position and an unlocked position. In some embodiments, the frame may further comprise a second guide shoulder, the actuator arm may further comprise a second guide post, and a second shape memory alloy wire may be strung between the second guide shoulder and the second guide post that rotates the actuator arm between an unlocked position and a locked position.

Abstract: An internal combustion engine control device that acquires the temperature of a catalyst disposed in an exhaust path, and detects an abnormal combustion that has occurred in a combustion chamber. The control device includes a gas control unit, which controls the amount of intake gas flowing into the combustion chamber and the temperature of exhaust gas flowing into the catalyst, and a fuel injection amount control unit, which controls the amount of fuel injected into the combustion chamber. The control device also includes an abnormal combustion inhibition mode selection unit that chooses a first mode, a second mode, or a third mode in accordance with the catalyst temperature when the abnormal combustion is detected. The first mode causes the gas control unit to suppress the occurrence of the abnormal combustion while raising the catalyst temperature.

Abstract: A spark-ignition supercharged internal-combustion gasoline engine is equipped with a system for variable actuation of the intake valves including a pressurized fluid chamber set between intake valve and a respective control cam, and an electrically actuated valve, the opening of which vents the pressure chamber so as to cause rapid closing of the valve, as a result of the respective elastic return means, even when the respective cam would tend to keep the valve open. The variable-valve-actuation system is used in combination with control cams of the intake valves shaped in such a way as to generate an intake valve lift profile including a boot portion with substantially constant lift. The boot portion is provided in the final part of the opening cycle of the intake valve, after bottom dead center.

Abstract: A turbine includes a turbine housing having two gas passages of substantially the same flow area. A nozzle ring is disposed in the housing and around the turbine wheel. The nozzle ring includes first and second outer rings, and an inner ring disposed between the first and second outer rings. First and second pluralities of vanes are disposed between the rings. The second outer ring has a thicker cross section than the first outer ring such that a larger flow area is created between the first outer ring and the inner ring than a flow area created between the second outer ring and the inner ring.

Abstract: An installation for storing thermal energy which can be obtained, for example, at times of overcapacities, from regenerative energy and then be stored is provided. The energy stored in a heat accumulator, a cold accumulator and in an additional heat accumulator can be, when needed, reconverted into electrical energy by circuits via a generator (G) while using a compressor and a turbine. The working gas is humidified by a humidification column, ideally until saturation, whereby, advantageously, a greater mass flow can be obtained at a lower volume flow. For this reason, more economical components can be used while simultaneously a high yield of the installation is achieved.

Abstract: An energy storage device for storing thermal energy, with a charging circuit for a working gas, is provided, having a compressor, heat accumulator and expansion turbine, the compressor and expansion turbine arranged on a common shaft, and the compressor connected on the outlet side to the inlet of the expansion turbine via a first line for the working gas, the heat accumulator wired into the first line, wherein the compressor is connected on the inlet side to a line, which is open to the atmosphere, and the expansion turbine is connected on the outlet side to a line, which is open to the atmosphere such that a circuit open to the ambient air is formed, wherein the expansion turbine is connected to the heat accumulator via a line for a hot gas such that the working gas in the expansion turbine can be heated by heat from the heat accumulator.

Abstract: The present invention provides a distributed combined cooling, heating and power generating apparatus with an internal combustion engine by combining solar energy and alternative fuel and a method thereof, the apparatus comprising: an energy storage system for combined reaction between solar energy and alternative fuel, a solar fuel internal combustion engine generating system, a lithium bromide refrigeration system for absorbing exhaust heat of flue gas of solar fuel, a reaction device for recovering exhaust heat of flue gas, a heat exchanger for recovering exhaust heat of exhaust gas and a cylinder jacket and water plate heat exchanger.

Abstract: An acoustically dampened gas turbine engine having a gas turbine engine combustor with an acoustic damping resonator system is disclosed. The acoustic damping resonator system may be formed from one or more resonators positioned within the gas turbine engine combustor at an outer housing forming a combustor basket and extending circumferentially within the combustor. The resonator may be positioned in a head region of the combustor basket. In one embodiment, the resonator may be positioned in close proximity to an intersection between the outer housing and an upstream wall defining at least a portion of the combustor. The acoustic damping resonator system may mitigate longitudinal mode dynamics thereby increasing an engine operating envelope and decreasing emissions.

Abstract: Embodiments of a Gas Turbine Engine (“GTE”) are provided, as are embodiments of a plasma flow-controlled intake system for deployment on a GTE. In one embodiment, the GTE includes a turbine section, a combustion section upstream of the turbine section, a compressor section upstream of the combustion section, and intake section upstream of the compressor section. The intake section includes a plenum, a first inlet fluidly coupled to the plenum, and a flow-obstructing structure projecting into the plenum and having an outer surface impinged by the airflow directed into the plenum through the first inlet during operation of the GTE. A first array of plasma actuators is disposed on flow-obstructing structure and, when activated, suppresses vortex shedding of the air flowing over the outer surface of the flow-obstructing structure.

Abstract: One embodiment of the present invention is a unique aircraft propulsion gas turbine engine. Another embodiment is a unique gas turbine engine. Another embodiment is a unique gas turbine engine. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for gas turbine engines with heat exchange systems. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith.

Abstract: A thermal/electrical power converter includes a gas turbine with an input couplable to an output of an inert gas thermal power source, a compressor including an output couplable to an input of the inert gas thermal power source, and a generator coupled to the gas turbine. The thermal/electrical power converter also includes a heat exchanger with an input coupled to an output of the gas turbine and an output coupled to an input of the compressor. The heat exchanger includes a series-coupled super-heater heat exchanger, a boiler heat exchanger and a water preheater heat exchanger. The thermal/electrical power converter also includes a reservoir tank and reservoir tank control valves configured to regulate a power output of the thermal/electrical power converter.

Abstract: A combustor section for a gas turbine engine includes a combustor vane which extends at least partially into a combustion chamber.

Abstract: An injector for a multipoint combustor system includes an inner air swirler which defines an interior flow passage and a plurality of swirler inlet ports in an upstream portion thereof. The inlet ports are configured and adapted to impart swirl on flow in the interior flow passage. An outer air cap is mounted outboard of the inner swirler. A fuel passage is defined between the inner air swirler and the outer air cap, and includes a discharge outlet between downstream portions of the inner air swirler and the outer air cap for issuing fuel for combustion. The outer air cap defines an outer air circuit configured for substantially unswirled injection of compressor discharge air outboard of the interior flow passage.

Abstract: A system includes a multi-tube fuel nozzle. The multi-tube fuel nozzle includes multiple mixing tubes. Each mixing tube includes an annular wall disposed about a central passage and an air inlet region configured to be disposed about a fuel injector extending into the central passage. The central passage extends from an upstream end to a downstream end of the annular wall relative to a direction of flow through the central passage. The air inlet region includes an air entry surface of the annular wall that gradually decreases in diameter in the direction of flow.