A blade force modeling method, a computing device and a computer storage medium

Abstract

The application provides a blade force modeling method, a computing device and a computer storage medium, which decomposes blade force into loss force and turning force, determines the size of the loss force based on the first law of thermodynamics, a momentum equation and an assumption that the size of the steady loss force is proportional to local airflow relative kinetic energy, determines the size of the turning force based on the momentum equation, an assumption that the size of the steady circumferential force is related to airflow circumferential relative speed and meridian speed, and determines the direction of the loss force and the turning force according to the relationship between the loss force and the turning force and airflow speed and a blade type geometric arc line, thereby reducing the calculation amount while ensuring the calculation accuracy, so that the internal flow condition of the compressor can be quickly and reliably obtained.

Claims

1. A method for modeling blade forces, characterized in that, The method includes: constant blade force Decomposed into steady loss forces that cause flow losses in the airflow. and the steady turning force that forces the airflow to turn in the blade passage. sum; The magnitude of the steady loss force is determined based on the first law of thermodynamics, the momentum equation, and the assumption that the magnitude of the steady loss force is proportional to the relative kinetic energy of the local airflow. The direction of the steady loss force is determined based on the local airflow velocity direction. Based on the momentum equation and the assumptions regarding the relationship between the magnitude of the steady circumferential force and the relative circumferential velocity and meridional velocity of the airflow, the magnitude of the steady turning force is determined. The direction of the turning force is determined based on the normal direction of the arc in the airfoil geometry. The method further includes: Blade forces include steady blade forces and unsteady blade forces. Unsteady blade forces... The decomposition into the sum of steady blade forces and unsteady disturbances includes: ,in, and These represent the unsteady loss force and the unsteady turning force in the unsteady blade forces, respectively. and These represent steady loss force and steady turning force, respectively. and These represent the unsteady loss force disturbance and the unsteady turning force disturbance, respectively. The unsteady perturbation is determined based on Taylor expansion; The determination of the unsteady disturbance based on Taylor expansion includes: The unsteady disturbance is determined based on the first-order Taylor expansion and the first-order delay equation, as follows: ,in, , , These represent the radial velocity, circumferential velocity, and axial velocity in the stationary coordinate system, respectively. This is the delay time.

2. The method as described in claim 1, characterized in that, The determination of the magnitude of the steady loss force, based on the first law of thermodynamics, the momentum equation, and the assumption that the magnitude of the steady loss force is proportional to the relative kinetic energy of the local airflow, includes: The momentum equations include three equations under the assumption of steady axisymmetry. The relationship between meridional entropy increase and steady loss force is determined by three equations based on the first law of thermodynamics and the steady axisymmetry assumption. The steady loss force coefficient is determined based on the relationship between the meridional entropy increase and the steady loss force, and the assumption that the magnitude of the steady loss force is proportional to the relative kinetic energy of the local airflow. The magnitude of the steady loss force is determined based on the steady loss force coefficient.

3. The method as described in claim 2, characterized in that, The expression for the assumption that the magnitude of the steady loss force is proportional to the relative kinetic energy of the local airflow is: ， in, This is the loss force coefficient. denoted as rotor speed, with units of r / min, where r is the radial coordinate.

4. The method as described in claim 2 or 3, characterized in that, The determination of the magnitude of the steady turning force, based on the assumptions of the momentum equation and the relationship between the magnitude of the steady circumferential force and the relative circumferential and meridional velocities of the airflow, includes: The momentum equation includes the circumferential momentum equation; The steady axisymmetric circumferential momentum equation is determined based on the steady assumption, the axisymmetric assumption, and the circumferential momentum equation. The expression for the magnitude of the steady circumferential force is determined based on the aforementioned steady axisymmetric circumferential momentum equation and the definition of the directional derivative in the meridional direction; Based on the expression for the magnitude of the steady circumferential force and the assumptions regarding the relationship between the magnitude of the steady circumferential force and the relative circumferential velocity and meridional velocity of the airflow, the steady circumferential force coefficient is determined. The magnitude of the steady turning force is determined based on the steady circumferential force coefficient and the steady loss force coefficient.

5. The method as described in claim 4, characterized in that, The assumed expression for the relationship between the magnitude of the steady circumferential force and the relative circumferential velocity and meridional velocity of the airflow is as follows: ， in, For steady circumferential force coefficient, This is the circumferential component of the unit direction vector in the opposite direction to the local airflow velocity. is the circumferential component of the unit direction vector of the arc normal in leaf geometry.

6. A computing device, comprising: One or more processors; Memory, used to store one or more programs. Wherein, when the one or more programs are executed by the one or more processors, the one or more processors implement the method of any one of claims 1 to 5.

7. A computer-readable storage medium storing computer-executable instructions for causing the computer to perform the method according to any one of claims 1-5.

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