Abstract: The present invention discloses a numerical simulation method for proppant transport considering wall-retardation effect, comprising the followings: establish a physical model of laboratory experiment on proppant transport with a large flat-panel device; establish a drag coefficient model considering wall-retardation effect according to the numerical simulation experiment; establish a computational geometric model; set boundary conditions and physical parameters of the geometric model according to the two-fluid simulation method for solid proppant quasi-fluidization; verify the grid independence of the computational geometric model to obtain the transport characteristics and placement pattern of the proppant in fractures. The present invention employs a numerical simulation method to study the migration and distribution patterns of proppant under the retardation effect of narrow walls during the hydraulic fracturing.

Abstract: The present invention discloses a numerical simulation method for proppant transport considering wall-retardation effect, comprising the followings: establish a physical model of laboratory experiment on proppant transport with a large flat-panel device; establish a drag coefficient model considering wall-retardation effect according to the numerical simulation experiment; establish a computational geometric model; set boundary conditions and physical parameters of the geometric model according to the two-fluid simulation method for solid proppant quasi-fluidization; verify the grid independence of the computational geometric model to obtain the transport characteristics and placement pattern of the proppant in fractures. The present invention employs a numerical simulation method to study the migration and distribution patterns of proppant under the retardation effect of narrow walls during the hydraulic fracturing.

Abstract: An agricultural aircraft for spreading granular fertilizer and a spreading method thereof. The agricultural aircraft includes an aircraft body, a power system, and a spreading device, where the spreading device is located at a front part of the aircraft body, and the aircraft body is also provided at the front thereof with a wind direction sensor and a wind speed sensor communicatively connected a controller; the spreading device includes a box body, a throwing disc, and a tray connected to the box body, where a left baffle plate and a right baffle plate with controllable opening angles are disposed on the tray; an upper part of the box body is a material box for storing granular fertilizer, a cavity for accommodating the tray and the throwing disc is disposed on one side of the box body.

Abstract: The present invention discloses an agricultural aircraft for spreading granular fertilizer and a spreading method thereof. The agricultural aircraft includes an aircraft body, a power system, and a spreading device, where the spreading device is located at a front part of the aircraft body, and the aircraft body is also provided at the front thereof with a wind direction sensor and a wind speed sensor communicatively connected a controller; the spreading device includes a box body, a throwing disc, and a tray connected to the box body, where a left baffle plate and a right baffle plate with controllable opening angles are disposed on the tray; an upper part of the box body is a material box for storing granular fertilizer, a cavity for accommodating the tray and the throwing disc is disposed on one side of the box body.