178results about How to "Improve flow stability" patented technology

A supersonic externally pressurized inlet comprising a generally scoop-shaped supersonic pressurized portion for diffusing a supersonic free jet. The supersonic pressurization portion includes a main wall having a leading edge and a throat downstream of the leading edge; and sides joined to opposed side edges of the main wall to form a generally scoop-shaped member. The sides preferably protrude far enough into the supersonic flow to encompass the initial oblique shock attached to the leading edge of the main wall. The main wall has an inner surface generally formed as an inclined sector of the surface of revolution, the inner surface of the main wall cooperating with the inner surfaces of the sides to form a three-dimensional external pressurized surface. The supersonic external pressurization inlet also includes a subsonic diffuser section arranged to receive airflow from the supersonic pressurization section and diffuse the airflow to subsonic conditions. The variable geometry inlet includes an outer ramp hinged about its forward edge and forming part of the inner surface of the spoon diffuser, the pivotal movement of the outer ramp being used to vary the throat size of the inlet. The subsonic diffuser includes an inner ramp hinged around its trailing edge to maintain a smooth transition from the outer ramp.

A modified vacuum actuated valve assembly and sealing mechanism is provided for improved sub-atmospheric flow stability characterized by the absence of delivery pressure spikes and flow excursions. The valve assembly includes a non-stationary thermoplastic seat and a stabber. The stabber is characterized by a top portion having a circular periphery designed to mechanically engage and disengage with an inner sealing surface of the thermoplastic seat. The sealing surface is coined to eliminate surface irregularities contained therein, thereby producing a relatively smooth coined mating inner sealing surface for the circular top portion of the stabber. The valve assembly also includes a modified bellows capable of fine tuning the delivery pressure of the valve assembly.

A compact flow control valve with high flow stability is arranged to comprises: a valve body made of resin including; a first passage formed in the valve body; a valve port communicating with the first passage; and a valve seat formed around the valve port; a valve element movable into contact with and away from the valve seat; a valve chamber formed around the valve seat; a second passage communicating with the valve chamber; and a flow adjustment rod for adjusting a flow rate of a fluid allowed to flow in the valve chamber, wherein the flow adjustment rod is adjustable in position to change an opening degree of the valve element relative to the valve seat for adjusting the flow rate, and the flow control valve further comprises an annular recess formed in an inner periphery of the valve seat formed surrounding the valve port and configured to prevent radial deformation of the valve port when the valve element is moved into contact with the valve seat.

The present invention is to provide a kind of multifunction passive and continuous fluid feeding system for external systems, the fluid-feed system including a storing and transmitting component, a measuring and regulating component, and a control unit characterized by: pressurizing from above fluid level surface of the feed fluid tank by high-pressure gas supply source to fulfill the passive fluid feeding function, performing the feed fluid measuring and regulating through the flow meter and flow control valve installed on the transmission pipe lines connecting to the external systems, fulfilling function of continuous fluid feeding by switching between two fluid-feed tanks, and combining the feed fluid requirements of the external systems through the control unit to achieve the multifunction fluid-feed art of automatic operation, continuous fluid feeding, and flow rate controlling. The present invention does not utilize high-head and high-pressure pumps as the driving components, thus it is not only cost-saving but makes easier in coping with various fluid-feed requirements by the external systems, hence, possessing potentials of extending applicability into various industrial fields.

A method and reactant gas bypass system for carrying out a plasma enhanced chemical vapor deposition (PECVD) process with improved gas flow stability to avoid unionized reactant precursors and thickness non-uniformities the method including providing a semiconductor process wafer having a process surface within a plasma reactor chamber for carrying out at least one plasma process; supplying at least one reactant gas flow at a selected flow rate to bypass the plasma reactor chamber for a period of time to achieve a pre-determined flow rate stability; and, redirecting the at least one reactant gas flow into the plasma reactor chamber to carry out the at least one plasma process.

The invention discloses a high-strength steel plate with the yield strength 1,000 MPa and a production method thereof. The steel plate comprises the following chemical components in percentage by weight: 0.05-0.08 percent of C, 0.1-0.3 percent of Si, 1-2 percent of Mn, less than or equal to 0.015 percent of P, less than or equal to 0.007 percent of S, 0.3-0.7 percent of Ni, 0.3-0.5 percent of Cr, 0.3-0.6 percent of Mo, 0.02-0.04 percent of Nb, 0.03-0.055 percent of V, 0.01-0.035 percent of Ti, 0.002-0.0035 percent of B and the balance of Fe and inevitable impurities, wherein the gas content [O] is controlled to be less than or equal to 0.002 percent and [N] is controlled to be less than or equal to 0.004 percent, Ti/N is more than or equal to 3.2, and the carbon equivalent index Ceq is less than or equal to 0.56 percent. The production method comprises the following steps of: performing continuous casting with an electromagnetic stirring technology, wherein the thickness of a continuously cast bloom after casting is not less than four times that of a finished steel plate; and heating a steel blank at the temperature 1,100-1,200 DEG C, rolling in a recrystallization region and a non-recrystallization region at two stages, performing relaxation temperature waiting for 5-20 seconds, quickly cooling to 300-450 DEG C at the speed 10-30 DEG C per second, draining water, stacking, slowly cooling, tempering the steel plate at the tempering temperature 400-600 DEG C, and preserving heat for 2-3 minutes per millimeter. The steel plate has high comprehensive performance, large specification coverage and greatly-lowered production cost and raw material cost in comparison to the conventional product of the same level, and can be widely applied to the fields of mines, engineering machinery and the like.

The invention discloses a hydraulic design method for a double-blade non-block centrifugal impeller. The double-blade non-block centrifugal impeller structurally comprises a front cover plate, blades and a rear cover plate. The hydraulic design method comprises the steps that (1) the main hydraulic geometrical parameters of the double-blade non-block centrifugal impeller are worked out based on a velocity coefficient method; (2) the shapes of the axial surfaces of the blades are controlled based on a quadratic Bezier curve control algorithm; (3) the molded line installation angles of the blades are controlled based on a quartic Bezier curve control algorithm; (4) optimization design is conducted on the double-blade non-block centrifugal impeller based on a non-dominated sorting genetic algorithm (NSGA) II; and (5) the double-blade non-block centrifugal impeller according with the given flow, the given lift, the given pump efficiency and the given rotating speed value is manufactured by using the data obtained in the step (1) to step (4) as the dimension parameters of the double-blade non-block centrifugal impeller. By the adoption of the double-blade non-block centrifugal impeller designed through the method, the flow capacity and the anti-twining capacity of the impeller can be improved, the internal flowing condition of the impeller is improved, and the operating stability and the hydraulic efficiency of the impeller are improved.

A method and system for stabilizing flow includes introducing a flow into a channel with a minimum cross-sectional dimension of less than three millimeters and triggering a release of one or more bubbles in the flow at one or more locations in the channel. The one or more locations are spaced in from an inlet and an outlet to the channel.

A fuel injector includes an orifice disc. The orifice disc includes a peripheral portion, a central portion, and an orifice. The peripheral portion is with respect to a longitudinal axis and extends parallel to a base plane. The peripheral portion bounds the central portion. The central portion includes a facet that extends parallel to a plane that is oblique with respect to the base plane. The orifice penetrates the facet and extends along an orifice axis that is oblique with respect to the plane. As such, the orientation of the orifice with respect to the longitudinal axis is defined by a combination of (1) a first relationship of the plane with respect to the base plane, and (2) a second relationship of the orifice axis with respect to the plane. A method of forming a multi-facetted dimple for the orifice disc is also described.

The invention relates to a lubricating oil additive, a preparation method thereof and lubricating oil containing the same. The lubricating oil additive has an acrylic acid series segmented copolymer structure and also has a general formula comprising at least one of (A-B)a, (A-B)b-A or (B-A)c-B, wherein A stands for a copolymer block consisting of (methyl) acrylic acid alkyl ester with alkyl with 1-3 carbon atoms; and B stands for a copolymer block consisting of (methyl) acrylic acid alkyl ester with alkyl with 4-30 carbon atoms, and the mass ratio of A to B is 1/99-40/60. Compared with the traditional acrylic acid series lubricating oil additive, the lubricating oil additive provided by the invention has good tackifying effect and can ensure that the viscosity index of the lubricating oil can be greatly improved with less addition amount, the low-temperature characteristics, the flowing characteristics and the shearing stability can be improved, the service life of the lubricating oil can be prolonged, energy resources can be saved, and the load on global environment is reduced.

The invention relates to a mass method/standard meter method micro-flow water flow standard device. The device comprises a water storage tank which is connected with the lower end of a surge tank through a water pump, a high-level water tank is connected with the surge tank, the surge tank and the high-level water tank are connected with a front detected-meter header of a horizontal detected-flow-meter placement pipeline through electric switching valves respectively, the front detected-meter header is connected with two horizontal expansion joints in parallel, detected flow meters with different calibers are installed through the horizontal expansion joints, the two horizontal expansion joints gather on a front standard meter header, three standard meters with different calibers are installed at the outlet of the front standard meter header and connected to a rear standard meter header, two vertical detected-flow-meter placement pipelines are connected through the rear standard meter header, detected flow meters can be installed on the vertical detected-flow-meter placement pipelines through vertical expansion joints, three redirectors with different calibers are arranged at the tail ends of the two vertical detected-flow-meter placement pipelines in a connected mode, and one water outlet of each redirector corresponds to a weighing container.

The invention relates to a centrifugal compressor using an asymmetrical bladed diffuser with variable blade consistencies in the circumferential direction, and belongs to the technical field of turbomachinery. The centrifugal compressor comprises a volute, a centrifugal impeller and the bladed diffuser. The inlet front edge positions and the bladed mounting angles are evenly distributed in the circumferential direction, the blade consistencies are asymmetrically distributed in the circumferential direction, and the consistencies are unequal in different circumferential positions. The blade consistencies are changed by changing the central angles (namely the front edge interval between every two adjacent blades) corresponding to flow channels. The compressor can effectively adapt to the downstream circumferential pressure distortion of the bladed diffuser, the nonuniformity of a flow field in the bladed diffuser is reduced, the flowing stability of the centrifugal compressor is effectively improved, and the stable working range of the centrifugal compressor is enlarged.

The invention discloses a dual-arm backward erosion corrosion testing device. The dual-arm backward erosion corrosion testing device comprises a bracket, a test groove, a computer feedback control system, an electrochemical workstation and two groups of transmission systems, wherein a heater is arranged in the test groove; each group of transmission systems comprises a frequency converter, a rotary table, a sample frame, a revolving shaft and a motor connected with the frequency converter; the motors are connected with upper ends of the revolving shafts; lower ends of the revolving shafts are vertically connected with the rotary tables; the sample frames are vertically connected with the revolving shafts; the computer feedback control system comprises a computer and a control cabinet; the heater and the two frequency converters are connected with the control cabinet; the control cabinet is used for controlling the two groups of transmission systems to drive the two revolving shafts to rotate reversely in order to drive the sample frames on the two rotary tables to rotate in the test groove; outer walls of the revolving shafts are provided with electrochemical assemblies which are connected with the electrochemical workstation, and rotation speed sensors which are connected with the computer. By adopting the dual-arm backward erosion corrosion testing device, dual-shaft reverse rotation is adopted, so that a more accurate relative motion speed can be obtained during rotation of a sample, the flow state stability of a medium can be improved, and an optimal erosion effect is achieved.

A premix burner, for example for a gas turbine, having a conical swirl generator (1) and a cylindrical mixing section (2) which follows it in the direction of flow, includes a high-pressure atomizer nozzle (10) with one or more fuel feed passages. The high-pressure atomizer nozzle (10) includes at least two outlet passages, through which liquid fuel enters the swirl generator (1), these passages being arranged off-center with respect to the longitudinal axis of the nozzle and being configured in such a way that the spray cone (11) of the fuel is oriented at an angle (β) with respect to the longitudinal axis of the swirl generator (1) which is smaller than the cone half-angle (α) of the swirl generator (1). The outlet passages in particular have an internal geometry with a conically narrowed section.

The invention discloses a pantograph head balance device. The pantograph head balance device comprises a balance rod system located under an upper arm rod, and the balance rod system comprises a first rod hinged to the upper end of a lower arm rod, a second rod hinged to the upper end of the upper arm rod, a fourth rod hinged to a pantograph head rotating shaft and a third rod of which one end is hinged to the free end of the second rod and the other end is hinged to the free end of the fourth rod; the other end of the first rod is hinged to the middle of the second rod, the upper end of the upper arm rod extends to form a connection part, and the connection part is hinged to the pantograph head rotating shaft. According to the pantograph head balance device, a multi-connecting rod balance device with multi-sectional design is adopted to replace a traditional structure of one straight balance rod, the rotation angle of the pantograph head can remain unchanged in the rising and falling process of a pantograph, and the current collection stability is improved. Due to the fact that the balance device is arranged under the upper arm rod in a hidden mode, the windward area of the pantograph is decreased, wind resistance in high speed operation is reduced, and the aerodynamic performance of the pantograph is improved.