[16] provided a mixture model with modified mass transfer expression based on the mechanics of evaporation and condensation for calculating cavitating flow, and this cavitation model was further developed to predict cavitating flows in high-temperature water by considering the thermodynamic effects and physical properties [17]. It is found that the length of the vapor distribution decreases with temperature increasing, and the prediction of the axial vapor fraction is in good agreement with the experimental data. Oil cavitation is adverse to the hydraulic system and its components. When cavitation occurs, the oil enters a gas-liquid two-phase state. This changes the physical properties of the hydraulic oil and affects the dynamic characteristics and stability of the whole hydraulic system. The existence of a gas phase reduces the efficiency, the actual transport capacity, and the quality of outlet flow of the positive displacement pump. As the cavitation develops, the energy generated by the growth and collapse of the bubble greatly impactsthe hydraulic system, causing pressure fluctuations in the hydraulic system. The entire hydraulic system can be seriously damaged under certain conditions. In order to improve the stability of the gear pump, it is significant to investigate the cavitation phenomenon in the gear pump. The study of Computational Fluid Dynamics (CFD) numerical simulations for gear pumps can be traced back to 1989 when [PERSON] et al. [18] proposed a detailed simulation program to investigate the performance of external gear pumps. Building on this foundation, [PERSON] et al. [19] introduced a simplified two-dimensional numerical approach to study the effect of cavitation on the volumetric efficiency of external gear pumps. More recently, [PERSON] et al. [20] developed a three-phase compressible model combined with an immersed boundary approach to predict cavitation in gear pumps, particularly in the presence of non-condensable gases (NCG). [PERSON] et al. [21] utilized the Immersed Solid Method (ISM) to simulate the operation of a gear pump under extreme conditions of high rotational speed, focusing on the effect of lateral clearance on flow rate. [PERSON] et al. [22] employed numerical methods to examine how the number of teeth affects the operation of a gear pump. Additionally, [PERSON] et al. [23] proposed a numerical model based on ANSYS CFX to study the impact of cavitation on the power consumption rate of gear pumps. In addition to gear pumps, there have been numerous CFD numerical simulation studies focusing on other systems where lubricating oil serves as the working medium. For instance, [PERSON] et al. [24] combined experimental and numerical analyses to evaluate the effects of cavitation on hydraulic proportional directional valves. [PERSON] et al. [25; 26] developed a one-dimensional fluid dynamic model of a damper, focusing on the influence of cavitation on the pressure distribution generated by textured surfaces in lubricated couplings of hydraulic machines. [PERSON] et al. [27] established a numerical model to support the analysis and future design of hybrid journal bearings for fuel pump applications. [PERSON] et al. [28] numerically investigated pressure pulsations and cavitation phenomena in a micro-Organic Rankine Cycle (m-ORC) system, with a particular focus on the behavior of the pumping system. Furthermore, [PERSON] et al. [29] proposed an improved cavitation model incorporating thermodynamic effects, which is particularly relevant for ORC systems operating under varying thermal conditions. The cavitation dynamics of pumps and the numerical calculations of polymeric fluids have been deeply investigated in the past few decades. However, many polymeric fluids such as hydraulic oil and lubricating oil have different physical properties from room-temperature water. Their thermodynamic effects and the specific influence of thermo-sensitive physical properties on cavitation dynamics in a wide range of temperatures are still not well understood.