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This paper proposes a novel design for a hybrid engine air-particle separator filter (HEAPS) that combines the vortex tube separator (VTS) with the inertial particle separator (IPS) to enhance separation efficiency. Helicopters often operate in harsh environments, such as deserts, and landing on unprepared runways poses a severe risk to turboshaft engines due to the ingestion of dust and sand. This can result in significant damage to the engine's rotating components, impacting its life, reliability, and performance. To protect the engine from erosion and damage, an engine air particle separator system (EAPS) is installed in the engine inlet. In this study, a comparative numerical simulation was conducted between the hybrid filter and the VTS using the commercial software ANSYS Fluent. The Reynolds-averaged Navier–Stokes equations (RANS) were used to simulate incompressible turbulent flow, and the trajectory of particles was tracked using the Discrete Phase Model (DPM). Particle trajectories and separation efficiency were analyzed for different particle sizes, inlet velocities, and bypass mass flow ratios between the scavenge channel and the core engine channel. The results show that the hybrid design provides excellent separation efficiency, with a recovery efficiency of over 97%.

This paper proposes a novel design for a hybrid engine air-particle separator filter (HEAPS) that combines the vortex tube separator (VTS) with the inertial particle separator (IPS) to enhance separation efficiency. Helicopters often operate in harsh environments, such as deserts, and landing on unprepared runways poses a severe risk to turboshaft engines due to the ingestion of dust and sand. This can result in significant damage to the engine's rotating components, impacting its life, reliability, and performance. To protect the engine from erosion and damage, an engine air particle separator system (EAPS) is installed in the engine inlet. In this study, a comparative numerical simulation was conducted between the hybrid filter and the VTS using the commercial software ANSYS Fluent. The Reynolds-averaged Navier-Stokes equations (RANS) were used to simulate incompressible turbulent flow, and the trajectory of particles was tracked using the Discrete Phase Model (DPM). Particle trajectories and separation efficiency were analyzed for different particle sizes, inlet velocities, and bypass mass flow ratios between the scavenge channel and the core engine channel. The results show that the hybrid design provides excellent separation efficiency, with a recovery efficiency of over 97%. [ABSTRACT FROM AUTHOR]

The separator with inner channels is designed to solve the inefficiency caused by particle collisions with the wall. Then the response surface methodology is used to optimize this novel separator with the aim of maximizing the separation efficiency and exhaust rate while minimizing the pressure drop simultaneously. Firstly, the Reynolds Stress model and the Euler-Euler model are taken to compare the novel and conventional structures. Secondly, five factors, including inlet velocity (v) of air-particle flow, number of inner channels, axial angle of inner channels, height of inner channels, and number of guide vanes, are selected in the Box-Behnken Design. Thirdly, the quadratic regression equations are established in multi-objective optimization. The research results demonstrate that separation efficiency is improved but the pressure drop is increased in the novel design. Additionally, too large inner channels can lead to a decrease in separation efficiency. The increased height of the inner channels has the most positive impact on the exhaust rate. And the optimization amplitude of the pressure drop is the most remarkable, which is presented as 13.87% at v = 2.5 m/s, 34.49% at v = 4.5 m/s, and 75.49% at v = 6.5 m/s, respectively. Furthermore, the separation efficiency of optimized designs is higher than that of conventional ones at each velocity. The relevant research results can provide an effective guide for improving the efficiency of separators.

The separator with inner channels is designed to solve the inefficiency caused by particle collisions with the wall. Then the response surface methodology is used to optimize this novel separator with the aim of maximizing the separation efficiency and exhaust rate while minimizing the pressure drop simultaneously. Firstly, the Reynolds Stress model and the Euler-Euler model are taken to compare the novel and conventional structures. Secondly, five factors, including inlet velocity (v) of air-particle flow, number of inner channels, axial angle of inner channels, height of inner channels, and number of guide vanes, are selected in the Box-Behnken Design. Thirdly, the quadratic regression equations are established in multi-objective optimization. The research results demonstrate that separation efficiency is improved but the pressure drop is increased in the novel design. Additionally, too large inner channels can lead to a decrease in separation efficiency. The increased height of the inner channels has the most positive impact on the exhaust rate. And the optimization amplitude of the pressure drop is the most remarkable, which is presented as 13.87% at v = 2.5 m/s, 34.49% at v = 4.5 m/s, and 75.49% at v = 6.5 m/s, respectively. Furthermore, the separation efficiency of optimized designs is higher than that of conventional ones at each velocity. The relevant research results can provide an effective guide for improving the efficiency of separators. [ABSTRACT FROM AUTHOR]

In textile printing and dyeing industry, a novel type of separator called high gravity rotary gas-liquid separator (HGRGS) is designed, which includes a rotary drum with multi-layer fins and an impeller. First, the structure and separation principle of HGRGS are introduced in this paper. Then, the flow field and separation efficiency are studied by CFD techniques. To ensure the accuracy of the numerical simulation, the results are verified by the available experimental data. Compared with the typical cyclone, the maximum pressure drop reduction rate in HGRGS is 64.7% when the gas enters at 10 m/s. Besides, for droplets less than 5 μm, the separation performance in HGRGS is more efficient and it will be greatly improved by 30% for 1 μm droplets. The numerical results also show that the tangential velocity inside the rotary drum is linear with the radius and the higher the rotating speed, the greater the tangential velocity. Moreover, the maximum tangential velocity between the forced and quasi-free vortex has moved to the vicinity of the outer wall, which is beneficial for droplets to move outward. Additionally, the droplets in HGRGS can be captured with enough residence time owing to the lower axial velocity than that in a typical cyclone.

Inertial Particle Separator (IPS) is widely used as an important inlet protection device for turbo-shaft aero engine to protect the core engine in seriously polluted environment. In order to improve the separation efficiency of the IPS, an investigation was conducted to study the influence of critical geometrical and aerodynamic parameters on IPS performance, and Response Surface Method（RSM）was applied to explore the interaction between different parameters and obtain the response of the IPS performance on different parameters. Results show the separation of the sand particle in the IPS is achieved by the inertial accumulation of the sand particle, the trajectories of particles with small size are dominated by flow direction while paths of particles with larger size are dominated by the individual particle inertia and bounce characteristics from the IPS walls. The separation efficiency of the IPS is not only affected by the single geometrical parameters or aerodynamic parameter, but also apparently influenced by the interaction effects between different parameters. The most conspicuous influencing factor for the IPS separation efficiency on the AC-Coarse dust is Math and the interaction effects between Ro1 and Math. IPS separation efficiency on the AC-Coarse dust is improved by 3.8% by multi-factors optimization based on RSM, and the sand particle with size larger than 8 micron can be completely separated.

In textile printing and dyeing industry, a novel type of separator called high gravity rotary gas-liquid separator (HGRGS) is designed, which includes a rotary drum with multi-layer fins and an impeller. First, the structure and separation principle of HGRGS are introduced in this paper. Then, the flow field and separation efficiency are studied by CFD techniques. To ensure the accuracy of the numerical simulation, the results are verified by the available experimental data. Compared with the typical cyclone, the maximum pressure drop reduction rate in HGRGS is 64.7% when the gas enters at 10 m/s. Besides, for droplets less than 5 µm, the separation performance in HGRGS is more efficient and it will be greatly improved by 30% for 1 µm droplets. The numerical results also show that the tangential velocity inside the rotary drum is linear with the radius and the higher the rotating speed, the greater the tangential velocity. Moreover, the maximum tangential velocity between the forced and quasi-free vortex has moved to the vicinity of the outer wall, which is beneficial for droplets to move outward. Additionally, the droplets in HGRGS can be captured with enough residence time owing to the lower axial velocity than that in a typical cyclone. [ABSTRACT FROM AUTHOR]

Inertial Particle Separator (IPS) is widely used as an important inlet protection device for turbo-shaft aero engine to protect the core engine in seriously polluted environment. In order to improve the separation efficiency of the IPS, an investigation was conducted to study the influence of critical geometrical and aerodynamic parameters on IPS performance, and Response Surface Method(RSM)was applied to explore the interaction between different parameters and obtain the response of the IPS performance on different parameters. Results show the separation of the sand particle in the IPS is achieved by the inertial accumulation of the sand particle, the trajectories of particles with small size are dominated by flow direction while paths of particles with larger size are dominated by the individual particle inertia and bounce characteristics from the IPS walls. The separation efficiency of the IPS is not only affected by the single geometrical parameters or aerodynamic parameter, but also apparently influenced by the interaction effects between different parameters. The most conspicuous influencing factor for the IPS separation efficiency on the AC-Coarse dust is Math and the interaction effects between Ro1 and Math. IPS separation efficiency on the AC-Coarse dust is improved by 3.8% by multi-factors optimization based on RSM, and the sand particle with size larger than 8 micron can be completely separated. [ABSTRACT FROM AUTHOR]