11 results about "Hydrodynamic resistance" patented technology

The invention discloses a method for calculating the opening and closing force of a miter gate based on the stroke acceleration of a hoist. According to the method, relevant parameters of the ship lock miter gate are obtained, the hydrodynamic resistance moment caused by the water level difference during opening and closing operation of the miter gate is calculated through a hydrodynamic resistance moment calculation formula considering the stroke acceleration of a miter gate hoist, then the maximum total resistance moment during opening and closing operation of the miter gate is calculated, and finally the opening and closing force of the miter gate is calculated. According to the calculation method, the dynamic water resistance moment can be calculated by directly using the gate submerging water depth, the gate door leaf width, the water level difference value and the stroke acceleration of the hoist, so that the opening and closing force is calculated, the process of converting the water level difference into the pressure intensity is omitted, and the influence of the stroke acceleration of the hoist is increased; and a more convenient calculation method is provided for estimating whether the maximum opening and closing force for opening and closing the gate exceeds the rated capacity of the hoist or not when the operation mode of the gate of the ship lock is changed.

The invention provides a running water vibration wave generator, which is a blade device which combines an oil-water vibration wave generating device with a driving motor and a driving shaft rotated by the driving motor to rotate and generates oil-water vibration waves through fluid resistance, and the blade device is positioned in water and vibrates due to oil-water resistance generated by rotation. The first vibration generating blade is used for generating vibration waves, first vibration is generated on the lower portion of the first vibration generating blade, first vibration waves and second vibration are generated according to oil-water resistance, and the warm flow generating part is located between the first vibration generating blade and the second vibration generating blade and used for generating warm flow. Even if the length is reduced in order to reduce the rotation radius of the first vibration generating blade and the second vibration generating blade as much as possible, the first vibration generating blade and the second vibration generating blade can easily vibrate and generate vibration waves. Therefore, by reducing the size, the installation space can be reduced to the maximum extent, various vibration waves can be generated, and the massage effect can be improved.

The present invention discloses a grooved scale unit and a drag-reducing, noise-suppressing and sound-absorbing covering layer based on a micro-spring tensioning structure, which is composed of a plurality of grooved scale units based on a micro-spring tensioning structure arranged end to end in a diamond array. The grooved scale unit based on the micro-spring tensioning structure includes a grooved scale, an upper platform, a connecting hinge, a local resonance rod, a local oscillator, a spring and a lower platform. The grooved scale is fixed to the upper end face of the upper platform, the longitudinally arranged local resonance rod is fixed to the upper and lower platforms respectively by a connecting hinge, and one end of the transversely arranged local resonance rod is fixed to the lower platform by a hinge, and the other end is connected to the upper and lower platforms by a spring. The present invention can well simulate the process of the scale tail generating low-speed vortices to suppress turbulence during the swimming process of carp fish, thereby reducing fluid resistance and hydrodynamic noise. The micro-spring tensioning structure has good multi-dimensional vibration absorption characteristics, which can effectively weaken the transmission of vibration noise inside and outside the covering layer.

The present invention relates to stepped hull boats featuring cambered planing surfaces and is intended to reduce hydrodynamic resistance and improve efficiency of such boats in displacement and transitional modes by means of specifically shaped retractable fairings not compromising the operation of boats in the main high-speed planing mode, which is achieved by equating the angles of inclination of tangents to contours of the cambered surface and the fairing in vertical longitudinal sections at the trailing edge of the cambered surface and specific progression of the tangents along said contours, which results in the formation of a bulge in the front part of the fairing, which bulge, in the displacement and transitional modes of operation, protrudes downwards below the trailing edge in projection onto the transverse plane, whereas in the planing mode, the bulge, like the entire fairing, is located above said trailing edge.

The present application provides a flow passage structure, a fluid measuring device and a fluid control device, which are fixed without exerting unnecessary force on a fluid resistance member and ensure sealing, and comprise a pipe member (11a, 11b) constituting a flow passage (R), a ceramic fluid resistance member (2) provided in the flow passage (R) and having one or more resistance flow passages (2a), and a fixing mechanism (3) fixing the fluid resistance member (2) in the flow passage (R) by being clamped by the pipe member (11a, 11b), the fixing mechanism (3) having a sealing portion (4) sealing an outer circumferential surface of the fluid resistance member (2) and a pressing and fixing portion (5) pressing and fixing the outer circumferential surface of the fluid resistance member (2), the sealing portion (4) and the pressing and fixing portion (5) being provided at least at different positions in the axial direction of the fluid resistance member (2).

A coupling device for connecting an unmanned underwater vehicle to a floating vehicle in a body of water has a connecting device configured to be connected mechanically and / or electrically and / or for data exchange to the unmanned underwater vehicle in the body of water; and a hydrodynamic resistance structure configured to cause on the coupling device a counter force opposing the forward motion of the coupling device in the body of water.

The utility model discloses a fishtail reciprocating swing structure of a robotic fish, which belongs to the technical field of mechanical fishtail swing and comprises a mounting box, a rotating disc is rotatably connected in the mounting box, and a swing rod capable of swinging back and forth is arranged at the top of the rotating disc. According to the utility model, the extension assembly is arranged, the electric push rod drives the extension plate to be relatively unfolded through the movable plate, the fixed plate and the linkage rod, the driving length and the fishtail area are accurately adjusted through the electric push rod, the short driving length is matched with the small-area fishtail to reduce the fluid resistance and improve the vibration adaptability, and the driving power is obviously optimized; the large-area fish tail is combined with the long driving length, larger thrust is generated at the low speed by enhancing the swing amplitude and the water body accumulation effect, the heavy load or starting requirement is met, stepless switching between the high-speed cruise mode and the low-speed high-thrust mode is achieved, and the structure can meet different application requirements.

To provide a structure which can reduce a pressure resistance received by an object from a fluid.SOLUTION: A structure for reducing a resistance of a fluid includes: a first face in contact with the fluid; a friction part 25 positioned on the first face and expanding in a facial first direction along the first face; and a first smooth part positioned on the first face and adjacent to the friction part 25 in a facial second direction that crosses with the facial first direction. The friction part 25 includes a plurality of first guide structures 31 aligned in the facial first direction and guiding the fluid toward the first smooth part. The first guide structure 31 includes a first end part extending toward the first smooth part. The first end part has a first inclination angle of over 0° to less than 90° with respect to the facial first direction.SELECTED DRAWING: Figure 4

The invention relates to an Intelligent Maneuvering System for Easier Boat Handling, which is an accessory for boating and boat maneuvering. This system enables easy and precise boat maneuvering based on actual measurements, computer modeling, and mathematics, according to the control values provided by a Joystick or a mobile phone App. It allows the boat to be maneuvered in the desired heading with the required force and rotation around its vertical axis. This significantly enhances the boat's maneuverability and truly enables agile movement of the boat in the desired manner.The system consists of three propulsion propeller drives, one of which may be the original bow thruster of the boat. Propeller drives are installed in the boat with an angular offset about 120 degrees, in which case the reference values for their six infinitely adjustable force vectors are calculated by the microcomputer to achieve the desired maneuvering effect.Using the maneuvering system's calculation software and the thrust forces of the infinitely adjustable motor drives, the boat can be rotated in place, driven in any arbitrary direction while keeping the bow heading unchanged, or rotated during linear motion.On the boat (FIG. 2), (1) three propeller drives (3) and (5) are installed, whose rev is controlled by the motor controller (23) or the hydraulic system valve (24). The Joystick (28) steering values are converted into thrust control commands for each motor controller in the maneuvering mathematics calculation.The content of the patent claims specifies a propulsion system implemented with three motor drives (3) and (5) arranged 120° apart, where the power of each motor drive (3) and (5) is controlled individually according to the maneuvering command given by the Joystick (28) based on the vector mathematics calculations performed by the control system's software taking into account the actual installing locations and dimensions of propeller drives relative to the COB as well as the effects of changes in hydrodynamic resistance when maneuvering in different directions, as determined by CFD calculations.

This invention relates to the technical field of fluid microvelocity measurement, and proposes a method, system, and apparatus for fluid microvelocity measurement. The method includes the following steps: two microneedles are fixed in the fluid to be measured, and droplets or bubbles are injected into the microneedles under controlled conditions, with the droplets or bubbles suspended at the intersection of the tops of the two microneedles; images are acquired to obtain the morphological parameters of the droplets or bubbles in the fluid to be measured; a flow velocity calculation formula is constructed based on the energy relationship between the surface tension of the droplets or bubbles and the fluid resistance; the flow velocity of the fluid to be measured is obtained and output based on the morphological parameters of the droplets or bubbles and the flow velocity calculation formula. This invention relies on the energy relationship between the surface tension of the droplets or bubbles and the fluid resistance to convert the flow velocity change into observable droplet or bubble interface displacement deformation, thereby obtaining the fluid flow velocity. It has a simple structure, low cost, and high stability.

The subject of the present invention is a safety braking device (1) for a steering system (100) of a vehicle, comprising a cylinder (2) that delimits a housing (3), a piston (4) housed in the housing (3) of the cylinder (2), wherein the piston (4), together with the housing (3), delimits a first chamber (5) and a second chamber (6), at least one connection element (7) configured to fluidically connect the first chamber (5) and the second chamber (6), wherein the first chamber (5), the second chamber (6), and the connection element (7) are configured to contain a working fluid (F), wherein the piston (4) is translatably movable in the housing (3) of the cylinder (2) by moving the working fluid (F) through the at least one connection element (7) from the first chamber (5) to the second chamber (6), and / or vice versa, wherein the piston (4) is indirectly connectable to a steering wheel (101) of the steering system (100) such that a rotation of the steering wheel (101) is transformed into a translation of the piston (4) in the housing (3) of the cylinder (2), and vice versa, and such that a translational speed of the piston (4) and a rotational speed of the steering wheel (101) are mutually correlated, wherein the safety braking device (1) comprises fluid resistance means (8, 9) arranged along the at least one connection element (7), wherein the fluid resistance means (8, 9) are configured to selectively control a fluid flow rate of the working fluid (F) from the first chamber (5) to the second chamber (6), and vice versa, such that when the fluid flow rate of the working fluid (F) is below a threshold flow rate and / or the translational speed of the piston is below a threshold translational speed and / or the rotational speed of the steering wheel is below a threshold rotational speed, the working fluid (F) passes through the at least one connection element (7) from the first chamber (5) to the second chamber (6), or vice versa, without hindering the translation of the piston (4) and the rotation of the steering system (100), and when the fluid flow rate of the working fluid (F) reaches the threshold flow rate and / or the translational speed of the piston reaches the threshold translational speed and / or the rotational speed of the steering wheel reaches the threshold rotational speed, the working fluid (F) is hindered or blocked from passing through the at least one connection element (7) from the first chamber (5) to the second chamber (6), or vice versa, thereby hindering or blocking the translation of the piston (4) and the rotation of the steering system (100).