65results about How to "Good drag reduction effect" patented technology

The invention provides an aviation anti-drag film curing process parameter optimization method and system oriented to multiple substrates, and relates to the technical field of data processing. By activating a light-heat combined curing process, reading substrate data of the substrates, establishing a surface layer curing index of an aviation anti-drag film, and configuring light curing parameters, the curing process parameters of the aviation anti-drag film are optimized; the surface state data of the aviation anti-drag film subjected to photocuring is collected, the temperature change gradient is set through ground state data, stage division is conducted on thermocuring, stage temperature change gradient self-optimization is conducted according to feedback data, feedback constraint and stage division results of temperature monitoring points, photocuring enhancement is conducted, and curing production of the aviation anti-drag film is completed. The technical problem that in the prior art, in the curing process of the aviation drag reduction film, temperature control is not accurate, curing is not uniform, and consequently the drag reduction performance is reduced is solved. And the technical effects of accurately controlling the temperature in the curing process of the aviation anti-drag film, improving the curing uniformity and enhancing the overall anti-drag performance of the anti-drag film are achieved.

The invention relates to a preparation method of a'microstructure-liquid-like surface 'underwater drag-reduction, noise-reduction and antifouling multifunctional composite coating, and belongs to the field of underwater equipment. The multifunctional composite coating provided by the invention comprises an anti-drag microstructure arranged on the surface of a substrate and a liquid-like surface arranged on the surface of the anti-drag microstructure, and the liquid-like surface retains the original morphology of the anti-drag microstructure. According to the micro-structure, the distance between the wall face and a turbulent vortex can be increased, the frequency and strength of a flow vortex pair can be restrained, and resistance reduction is achieved; and on the liquid-like surface, resistance reduction can be achieved by enabling fluid to generate wall face slippage and reducing the speed gradient of the fluid on the boundary. The two mechanisms of action are different but do not interfere with each other, and a better drag reduction effect can be achieved through the synergistic effect. Meanwhile, the composite coating can achieve the noise reduction effect by reducing the turbulence intensity of the wall face. In addition, the liquid-like surface can resist adhesion of marine organisms, the integrity of the microstructure is guaranteed, and therefore the long-term drag reduction effect is achieved.

The invention discloses a shear-resistant high-drag-reduction high-viscosity slickwater drag reducer and a preparation method thereof, and belongs to the field of deep well / extra-deep well volume fracturing. The drag reducer is formed by polymerizing acrylamide, sodium acrylate, a sulfonate ion-containing hydrophobic monomer, a hydrophobic unit micro-block regulating agent, a molecular weight grade regulating agent and a composite initiator, and the drag reducer is prepared through the special sulfonate ion-containing hydrophobic monomer, the hydrophobic unit micro-block regulating agent matched with the hydrophobic monomer and polymer molecular weight control. The dissolving property and the tackifying property of the polymer are obviously improved; the shear degradation resistance of the drag reducer is improved; excellent sand-carrying performance and drag reduction performance are achieved; the slickwater drag reducer overcomes the defects that an existing slickwater drag reducer is weak in anti-shearing capacity, rapid in drag reduction rate reduction, poor in sand carrying performance and the like, meets the special requirement of deep / ultra-deep oil and gas reservoir fracturing for fracturing fluid rheology, provides key material support for development of deep / ultra-deep oil and gas resources, and guarantees the efficient development target of the deep / ultra-deep oil and gas resources.

The invention belongs to the technical field of tunnel engineering, and particularly relates to shield tunneling machine anti-drag slurry for stacked tunnel construction and a use method of the shield tunneling machine anti-drag slurry. According to the anti-drag slurry, bentonite, anhydrous Na2CO3 and water are used as main raw materials, a certain amount of a lubricant and a nanometer material are added into the slurry to prepare the anti-drag slurry, the stress condition between a shield tunneling machine shell and a soil body is monitored in real time, the grouting amount and the grouting pressure of the anti-drag slurry are dynamically adjusted according to the change of soil pressure, and therefore the anti-drag effect of the shield tunneling machine is achieved. The friction force between the shield tunneling machine shell and the surrounding soil body can be reduced, disturbance of the shield tunneling machine shell to the soil body is reduced, consolidation settlement of the soil body in the later period is reduced, and materials and methods are provided for stacked tunnel construction.

The invention discloses fish mucus-methacrylated gelatin hydrogel with lubrication and resistance reduction performance and a preparation method of the fish mucus-methacrylated gelatin hydrogel. The preparation process of the hydrogel comprises the following steps: firstly, preparing a methacrylated gelatin hydrogel (GelMA) precursor by utilizing an amidation reaction of methacrylic anhydride (MA) and gelatin (Gel), and then realizing gelation by utilizing hydrogen bond interaction of a fish mucus freeze-dried product (MC) and GelMA and photo-crosslinking of the GelMA precursor and polyethylene glycol diacrylate (PEGDA) under ultraviolet light of 365nm. The mucus-methylacryloylated gelatin hydrogel (MC-GelMA) is obtained after the mucus-methylacryloylated gelatin hydrogel is prepared. The hydrogel prepared by the preparation method disclosed by the invention has excellent swelling resistance and mechanical strength. Meanwhile, the hydrogel also has good lubrication and drag reduction performance, and can be used as a ship drag reduction material.

The invention belongs to the technical field of oil exploitation, and particularly relates to an acid liquor thickening agent as well as a preparation method and application thereof. The synthesis method comprises the following steps: adding butylene glycol, 4, 4 '-diaminostilbene-2, 2'-disulfonic acid, (2-acrylamido ethyl) phosphonic acid, monopotassium phosphate and deionized water into a first reactor, uniformly stirring, and adjusting the pH value to 7-8; (3-acryloyloxypropyl) tri (trimethylsiloxy) silane, deionized water, hydroxypropyl methyl cellulose, OP-10 and monopotassium phosphate are sequentially added into a second reactor, and the pH is adjusted to be 7-8; adding an initiator into a high-position dropwise adding tank, dropwise adding the initiator into a second reactor, quickly adding the mixed liquid in the first reactor when the viscosity begins to rise, heating, and carrying out heat preservation reaction to obtain viscous liquid; and drying and granulating to obtain the product. The invention has the advantages of simple synthesis, high apparent viscosity, strong shear resistance, good salt-resistant and hardness-resistant effects, and good drag reduction effect.

The invention discloses a shear-resistant high-drag-reduction medium-viscosity slickwater drag reducer and a preparation method thereof, and belongs to the field of deep well / extra-deep well volume fracturing. The drag reducer is formed by polymerizing acrylamide, a sulfonate ion-containing hydrophobic monomer, a hydrophobic unit micro-block regulating agent, a molecular weight grade regulating agent and a composite initiator, and the drag reducer is prepared by controlling the special sulfonate ion-containing hydrophobic monomer, the hydrophobic unit micro-block regulating agent matched with the hydrophobic monomer and the molecular weight of a polymer. The dissolving property and the tackifying property of the polymer can be obviously improved; the shear degradation resistance of the drag reducer is improved; excellent sand-carrying performance and drag reduction performance are achieved; the drag reducer overcomes the defects that an existing drag reducer is weak in anti-shearing capacity, fast in drag reduction rate reduction, poor in sand carrying performance and the like, meets the special requirements of deep / ultra-deep oil and gas reservoir fracturing for fracturing fluid rheology and shaft high drag reduction, provides key material support for development of deep / ultra-deep oil and gas resources, and guarantees the efficient development target of the deep / ultra-deep oil and gas resources.

The invention discloses a low-friction high-sand-carrying temperature-resistant shear-resistant high-viscosity linear adhesive and a preparation method thereof, and belongs to the field of deep well / extra-deep well volume fracturing. The linear adhesive is formed by polymerizing acrylamide, sodium acrylate, a sulfonate ion-containing hydrophobic monomer, a hydrophobic unit micro-block regulating agent, a molecular weight grade regulating agent and a composite initiator, and the linear adhesive is prepared by controlling the special sulfonate ion-containing hydrophobic monomer, the hydrophobic unit micro-block regulating agent and molecular weight. The dissolving property and the tackifying property of the polymer can be obviously improved; the anti-shearing performance of the linear adhesive is improved; excellent sand-carrying performance and drag reduction performance are achieved; according to the present invention, with the linear gel, the defects of weak anti-shearing ability, rapid drag reduction rate reduction, poor sand carrying performance and the like of the existing linear gel are overcome, the special requirements of deep / ultra-deep oil and gas reservoir fracturing on fracturing fluid rheology and shaft high drag reduction can be met, the key material support is provided for the development of deep / ultra-deep oil and gas resources, and the efficient development target of the deep / ultra-deep oil and gas resources is ensured.

The invention discloses a natural gas transportation pipeline drag reduction structure, an optimization method and a system, and relates to the field of pipeline structures. The problems that groove drag reduction in the field of natural gas pipeline transportation aims at small-diameter pipelines, most grooves are in a traditional v shape, and the drag reduction effect is not remarkable enough are solved. The resistance reduction structure comprises a plurality of semicircular groove structures with alternate widths and widths; wherein the width of the wide groove is twice that of the narrow groove. The optimization method comprises the following steps: establishing a smooth pipeline and a model with a wide-narrow alternate semicircular groove on the wall surface; carrying out structured grid division on the smooth pipeline and the wall surface with the wide and narrow alternate semicircular grooves; numerical simulation is conducted through Fluent fluid simulation software, and a turbulent flow structure in the pipeline is obtained; and the drag reduction rate is calculated, and the final natural gas transportation pipeline drag reduction structure is determined according to the drag reduction rate. By reducing the resistance, the amount of conveyed gas can be increased under the same energy consumption, or the energy consumption is reduced under the condition of keeping the same flow, so that the overall conveying efficiency is improved.

The intelligent plasma turbulence friction resistance reduction control system based on deep reinforcement learning comprises environment building, an upper computer and a controller, and the environment building comprises a high-voltage power supply, a plasma exciter, a state sensor, an evaluation sensor and a signal acquisition board card. The invention further provides an intelligent plasma turbulence friction resistance reduction method based on deep reinforcement learning. According to the invention, a hot line and a hot film are selected as sensors, array dielectric barrier discharge plasma with quick response is used as an exciter, and a control strategy of an intelligent agent is learned and optimized through continuous high-speed interaction between a deep reinforcement learning algorithm deployed in a computer and an FPGA controller and a turbulent boundary layer. And finally, real-time closed-loop control of turbulence friction resistance reduction is realized. Compared with traditional open-loop control, the method has the advantages of being better in adaptability under complex incoming flow, higher in drag reduction energy efficiency and the like.

The invention provides a plant protection spray head and a plant protection spraying device. The plant protection spray head comprises a shell, an isolation cylinder is coaxially sleeved with the shell, and an inner cavity with the left end open and the right end closed is formed between the shell and the isolation cylinder; a jet flow cavity with the right end open and the left end closed is formed in the isolation cylinder. A plurality of jet flow holes used for communicating the inner cavity with the jet flow cavity are formed in the barrel wall of the isolation barrel, and a set angle is formed between the jet flow holes and the axis of the inner cavity. By changing the internal structure of the plant protection sprayer, the liquid medicine flowing condition is improved, energy loss is reduced, and the liquid medicine utilization rate is increased. The plant protection spraying device can flexibly adjust the angle and direction of the spraying head according to the forms and growth stages of different crops, the utilization rate of pesticide is increased, and environmental pollution is reduced.

The invention belongs to the technical field of polymer composite materials, and particularly relates to a preparation method of a super-smooth surface based on modified composite particles, which comprises the following steps: spraying an organic-inorganic hybrid adhesive on the surface of a substrate for curing, and then spraying a modified composite particle dispersion liquid on the surface of the organic-inorganic hybrid adhesive for curing, thereby obtaining the super-smooth surface based on the modified composite particles. And finally, soaking the substrate loaded with the modified composite particles in lubricating oil added with a photoinitiator, and irradiating under ultraviolet light to obtain the super-smooth surface based on the modified composite particles. The prepared super-smooth surface based on the modified composite particles is excellent in performance, and the wear resistance, the mechanical strength and the like of the super-smooth surface can be enhanced.

The invention relates to the technical field of drag reducer preparation, and in particular to a method for producing a salt-resistant drag reducer for oil well fracturing. S1.1, weighing the following raw materials in parts by weight: 27-32 parts by weight of a modified polymer, 0.6-1.1 parts by weight of a cross-linking agent, 0.1-0.3 parts by weight of an antioxidant, 2-6 parts by weight of an acetate buffer, 0.6-0.8 parts by weight of a surfactant, 0.02-0.04 parts by weight of a benzalkonium chloride biocide, and 0.2-0.4 parts by weight of a bentonite suspending agent; wherein, the modified The polymer is prepared by copolymerization of acrylamide, crotonic acid and acrylic acid phosphonate in a mass ratio of 7:2 to 4:10 to 13; S1.2, adding the above raw materials and continuously stirring to obtain a salt-resistant drag reducer; crotonic acid, acrylic acid phosphonate and acrylamide are used to prepare a modified polymer, and carboxyl and phosphonic acid groups are introduced into the polyacrylamide, thereby enhancing the water solubility of the polymer and, at the same time, improving the coordination ability of the modified polymer with the zirconium ions in the cross-linking agent, thereby improving the salt resistance and drag reduction effect of the modified polymer.

The invention belongs to the technical field of hydrodynamic drag reduction, and discloses an underwater vehicle bionic drag reduction system based on drag reducer infiltration, which comprises an unpowered pressurizing mechanism and a drag reducer bionic injection mechanism, the unpowered pressurizing mechanism comprises a water inlet opening, a water inlet channel, a movable cover plate, a gas storage cavity and a one-way conduction Tesla valve, the drag reducer bionic injection mechanism comprises a grid supporting body, a grid channel, a double-layer elastic film, an elastic brace and a micro groove. When the underwater navigation body is in an underwater static state, the movable cover plate is tightly closed under the action of gas in the gas storage cavity, at the moment, the gas in the gas storage cavity cannot enter the double-layer elastic film, and the elastic brace is in a closed state; when the underwater navigation body is in an advancing state, the movable cover plate is opened under the influence of water flow pressure, gas in the gas storage cavity enters the double-layer elastic film through the one-way conduction Tesla valve to be pressurized, and the resistance reduction liquid overflows to the outside through the elastic supporting baffle. The device is applied to the field of outflow flow and can adapt to different operation conditions, and flow resistance is effectively reduced.

The invention belongs to the technical field of ship resistance reduction devices, and discloses a bubble resistance reduction device and a ship. The bubble drag reduction device comprises a gas generator, a bubble generator and a bubble breaker. The gas generator can generate compressed gas. The bubble generator is installed at the bottom of the ship and communicates with the gas generator, and compressed gas generates first bubbles through the bubble generator to be discharged. And the bubble breaker is positioned at the downstream of the bubble generator and is communicated with the bubble generator. The bubble breaker has an open state and a closed state, when the bubble breaker is in the open state, the first bubbles are broken into second bubbles through the bubble breaker, and the second bubbles flow into the bottom of the ship; when the bubble breaker is in a closed state, the first bubbles are directly discharged and flow into the bottom of the ship, the universality is high, and the drag reduction effect is good; structural operation is simple, and cost is low. The ship comprises a ship body and the bubble drag reduction device, and the bubble drag reduction device is located at the bottom of the ship body, so that the ship is high in overall operation efficiency and low in cost.

The utility model belongs to the technical field of screw drilling tools, and particularly relates to an all-metal high-frequency supporting and pressing prevention tool which comprises a vibration shell, a drainage piece, a flow guide piece, a semi-ring, a lock cap, a back cap, a bearing, an anvil, an impact hammer, a valve plate, a throttling nozzle, an upper wear-resistant seat, a clamp spring, a mandrel assembly, a wear-resistant plate, a lower wear-resistant seat and a lower seat connector. The device can be ensured to resist high temperature of 180-260 DEG C and frequency of 30-60 Hz in a low-pressure state, and still has higher oscillator energy and better resistance reduction effect when being used in an ultra-deep well.

The invention relates to the field of oil and gas gathering and transportation, in particular to a drag reducer for oil and gas gathering and transportation and a preparation method of the drag reducer, and solves the problems that poly-alpha-olefin drag reducers are insufficient in shear resistance, and nano drag reducers are unstable in drag reduction effect and poor in drag reduction effect. Dispersing graphene oxide in an alkaline solution, dropwise adding the dispersed graphene oxide into deionized water containing carboxymethyl cellulose, adding a catalyst, and carrying out a heating reaction to obtain a miniature elastomer; the preparation method comprises the following steps: preparing a micro elastomer, oxidizing the micro elastomer to form alkali liquor containing an activated nano material, modifying the activated nano material by using a polyphenol compound, and modifying a long-chain hydrophobic structure to obtain the hydrophobic drag reducer. The oil gas drag reducer prepared by compounding the graphene oxide and the cellulose and constructing a plurality of hydrophobic long chains is excellent in drag reduction effect and high in shear resistance.

The invention discloses an underwater vehicle head structure capable of slowly releasing a drag reducer, and belongs to the field of underwater drag reduction of vehicles. Comprising a head cone section and a head circular truncated cone section which are coaxially and fixedly connected, one end of the head circular truncated cone section is in sealed connection with the head cone section, a cavity structure for containing a drag reducer solution is arranged at the joint, and the other end of the head circular truncated cone section is in sealed connection with a navigation body middle section; the head cone section is a rotary body porous medium which is close to a cone, the cone vertex of the head cone section is a molded line stagnation point which forms a conical molded surface, the axial height at the stagnation point is the largest, and the axial thickness is in a change rule of gradually decreasing from the stagnation point to the edge of the bottom end. The defects that in the prior art, a drag reducer solution cannot evenly wrap the whole vehicle, and the integrity of a shell of the vehicle is greatly damaged when the drag reducer is released are overcome.

The application provides a kind of mixed laminar flow control tail optimization design method of comprehensive multi-condition and multi-constraint, comprising the following steps: according to the optimization target and constraint condition of multiple actual conditions of vertical tail, the optimization mathematical model of vertical tail is established;Design variables are constructed;The design variables include vertical tail geometric parameter design variables and vertical tail suction coefficient design variables;Based on the vertical tail reference configuration, the optimization design space of each design variable is determined;Optimization design is carried out.The application has good multi-condition and multi-constraint processing capability, can consider the balance of friction resistance and pressure difference resistance in optimization design, while ensuring that the stall characteristics of vertical tail do not deteriorate during take-off and landing stage, and the laminar flow range of airfoil does not change abruptly under small side slip state, and can consider various complex engineering constraints, thereby effectively improving the drag reduction effect of mixed laminar flow control tail, and making the design result more in line with actual engineering needs.

The invention relates to the technical field of pipelines, discloses a turbulence inhibitor of airflow, preparation and application of the turbulence inhibitor and a gas conveying method, and aims to solve the problem of over-high energy consumption caused by pipeline friction resistance in pipeline transportation of gas. The turbulence inhibitor comprises microparticles, the length of the microparticles is larger than or equal to eta and smaller than or equal to Lx, and Lx is the turbulence integral scale; eta is the Kolmogorov scale, eta = (v3 / epsilon) 1 / 4, and v is the kinematic viscosity of the airflow; epsilon is the turbulent flow energy dissipation rate. The turbulence inhibitor has the advantages of being high in applicability, excellent in drag reduction effect, economical, capable of saving energy and the like.

The invention relates to the technical field of automobile resistance reduction, in particular to a jet-propelled automobile rear wheel apron board and a method, the jet-propelled automobile rear wheel apron board comprises a jet module and a control module, the jet module comprises a nozzle and a corresponding control valve, the nozzle is arranged on the outer side of an automobile body above a rear tire, and the jet direction of an air outlet of the nozzle is vertically downward; the air injection control module comprises a total pressure sensor installed on the lower edge of a rear vehicle window, and the total pressure sensor monitors the total pressure condition of the rear wall face of the vehicle tail; the pressurization gas storage module comprises a gas storage tank used for storing pressure gas, and the gas storage tank is connected with the nozzle through the control valve; the global control module is used for collecting and processing data of the total pressure sensor, and controlling on-off of the control valve so as to control on-off of the gas storage tank and the nozzle; tiny airflow is jetted on the outer side of the vehicle body above the rear tire through the arranged nozzle, a pneumatic molded surface of the choke plate is formed, pneumatic resistance generated when wheel arch turbulence impacts the vehicle side airflow can be reduced, and the heat dissipation performance of the vehicle tire can be improved.

This invention discloses a variable cross-section tail wing suitable for FSAE racing cars, comprising a variable cross-section wing assembly, an upper sparsity wing, a first lower sparsity wing, a second lower sparsity wing, and endplates. The variable cross-section wing assembly consists of a main wing, a first flap, and a second flap; all three wings are variable cross-section wings. The variable cross-section wing is a small, continuous section raised at mid-span. The main wing, the first flap, and the second flap are sequentially mounted between the two endplates, roughly diagonally distributed, with the second flap featuring a grunt flap. The upper sparsity wing is mounted on the corner of the endplate, while the first and second lower sparsity wings are located near the bottom of the endplate. There are two endplates, symmetrically mounted on both sides, each featuring louvers, an outer edge flange, a leading edge notch, a trailing edge notch, and guide strips. The variable cross-section wing can reduce the turbulence caused by the headrest and minimize airflow slippage in the spanwise direction, resulting in a more uniform pressure distribution on the wing surface. The louver structure also reduces drag.

The invention belongs to the field of hypersonic active flow control, and discloses a drag reduction and heat protection system and method for a hypersonic aircraft, and the method combines two active flow control methods of energy deposition and magnetofluid flow control. The excellent drag reduction characteristic of energy deposition can bring a good drag reduction effect to an aircraft, meanwhile, energy deposition can serve as an auxiliary ionization technology, and the magnetic control effect of magnetic fluid flow control is improved by improving the fluid conductivity; due to the outstanding thermal protection performance of magnetic fluid flow control, an excellent thermal protection effect is brought to the aircraft after heat flow increase in a part of time periods caused by the energy deposition process is treated; meanwhile, the problems of resistance impact and oscillation caused by pulse energy deposition are fully inhibited under the action of the magnetic field Lorentz force; by the adoption of the method, a better hypersonic speed drag reduction and heat protection effect is achieved, the resistance borne by the hypersonic speed aircraft can be effectively reduced, the heat protection capacity of the aircraft is improved, and the method has wide application prospects.

The invention relates to a ship stern near-hull flow field adjusting method, which comprises the following steps of: 1, calculating a flow field near a hull according to a ship type and a working condition, and selecting a position where a spoiler is arranged; according to numerical calculation and a model test, a streamline near a stern and a hull is obtained, and a spoiler is arranged at the downward flowing position of the streamline in front of a stern shaft; 2, evaluating the drag reduction effect corresponding to each attack angle by adopting numerical calculation; comparing the total resistance value R0 before the spoiler is additionally mounted with the total resistance Ri of the ship after the spoiler is additionally mounted to determine which attack angle is finally adopted; 3, evaluating the ship resistance reducing effect of the spoiler, and judging whether the scheme of the spoiler continues to be modified or not according to the effect; the anti-drag effect of the device is verified by means of numerical calculation or model test and the like. The spoiler is arranged on the ship body in front of the tail shaft, and water flow is adjusted from obliquely downward flow to horizontally backward flow, so that the resistance of the ship is reduced, and the propelling efficiency of the propeller is improved.

The embodiment of the present application provides a method for correcting the position of a following vehicle, including: obtaining image information of a preceding vehicle; determining the vehicle type information of the preceding vehicle based on the image information of the preceding vehicle; determining the modification information of the preceding vehicle based on the image information of the preceding vehicle and the vehicle type information of the preceding vehicle; selecting a corresponding three-dimensional flow field simulation modification model based on the modification information of the preceding vehicle and the vehicle type information; and correcting the following position of the current vehicle according to the three-dimensional flow field simulation modification model. In this way, by obtaining the modification information of the preceding vehicle and the vehicle type information of the preceding vehicle, determining the three-dimensional flow field simulation modification model of the preceding vehicle based on the modification information and the vehicle type information of the preceding vehicle, and correcting the following position of the current vehicle based on the three-dimensional flow field simulation modification model of the preceding vehicle, the following position of the current vehicle is controlled to be within the negative pressure area of ​​the tail vortex of the preceding vehicle, thereby improving fuel economy.

The present invention discloses a drag reduction method for an impeller blade of a bionic fish scale structure, comprising the following steps: S1, obtaining a fish scale sample, selecting a fish scale with a standard appearance from the fish scale sample; S2, collecting the coordinate points of the outer contour of the fish scale, fitting and correcting the collected coordinate points to obtain a scale body curve; S3, arranging the scale body obtained in step S2 in a predetermined arrangement in the drag reduction area of ​​the airfoil body, and performing three-dimensional modeling to obtain the impeller blade. The present invention effectively reduces the airfoil surface resistance by arranging the scale body at intervals on the airfoil body surface, greatly improving its drag reduction performance, especially under low flow rate conditions, the drag reduction effect is very remarkable, greatly reducing the friction resistance between the wall and the fluid, achieving a significant improvement in the drag reduction characteristics, the airfoil surface shear stress is evenly distributed, the friction resistance is evenly distributed, the stress concentration problem is solved, and the phenomenon of hydraulic machinery blades being damaged due to stress concentration is effectively improved.

This invention discloses a method for preparing a superhydrophobic drag-reducing coating and its application in a manta ray-inspired submersible prototype, belonging to the technical field of underwater drag reduction and surface functional materials. The method includes: dispersing micron-sized SiO2 and nano-sized SiO2 in ethyl acetate to obtain a first dispersion; dispersing PDMS in ethyl acetate to obtain a second dispersion; mixing and stirring the first and second dispersions, then adding a curing agent and long-chain perfluoroalkyl silane PFDTES, followed by spraying and curing to obtain a PFDTES-PDMS@SiO2 coating. This invention achieves a water contact angle >150° and a roll-off angle <9° through the synergistic effect of PFDTES long-chain fluorination modification, PDMS flexible bonding, and the micro / nano dual-scale SiO2 hierarchical structure. In the manta ray-inspired submersible application, a drag reduction rate of 14.43% is achieved at a flow rate of 0.5 m / s, and the performance remains stable after 24 hours of dynamic water flow impact. This invention features a simple process, controllable cost, and is suitable for drag reduction functionalization of complex curved underwater equipment.

The present invention belongs to the technical field of oil extraction, and specifically relates to a drag reducer for shale gas reservoir fracturing and a preparation method thereof. The preparation method is as follows: 5-allyl-3-methoxy salicylic acid methyl ester, methacryloylethyl sulfobetaine, 1-vinyl-3-methylimidazolium tetrafluoroborate, allyl dimethyl (4-methoxyphenyl) silane, OP-10, sodium dodecyl sulfate, buffer salt, deionized water are sequentially added to a reactor, and stirred to form a uniform emulsion; heating, adding an initiator to a high-level tank, keeping warm, heating, cooling, adjusting the pH value, and obtaining a viscous liquid; granulation to obtain a final product drag reducer. The present invention has the advantages of a wide source of raw materials, a simple synthesis process, and no by-products; at the same time, the present invention has the characteristics of high viscosity and high drag reduction rate, and the apparent viscosity at a concentration of 0.2wt% is ≥200mPa.s, and the drag reduction rate is ≥75%.

The invention relates to the technical field of fracturing fluids, and discloses a drag reducer for fracturing and a preparation method thereof.15 # white oil, acrylamide, Tween 60, epoxidized triton, quaternized silane polymer and water are added into a stirrer and stirred, and the drag reducer for fracturing is obtained after stirring is finished. In the stirring process, an epoxy group in epoxidized triton and a hydroxyl group in a quaternized silane polymer are subjected to a ring-opening reaction to generate new hydroxyl groups, and the new hydroxyl groups and the quaternized silane polymer are crosslinked to form a compact network, so that the anti-shearing capability is better, meanwhile, the flow resistance of fluid in a shaft is reduced, and a better resistance reducing effect is achieved; a boron element in the quaternized silane polymer and a polymer in the drag reducer are subjected to a cross-linking reaction to form a stable gel, and the gel has excellent fracture forming and sand carrying capacities; wherein the quaternary ammonium salt and the silane also have a relatively good drag reduction effect.