An efficient method of simulating pressure loss in a separator with metal foam is reported. In this method, a metal foam is modeled as a porous media having homogenized permeability and inertial resistance coefficients. The permeability and inertial resistance coefficients were obtained by a numerical method that was validated by experimental data from a literature. Then the pressure drop in the separator with metal foam replaced by porous media was efficiently simulated under different working conditions, and the results were analyzed. It was found that the porous media had a great effect on the pressure drop in the separator. As pores per inch (PPI) and rotating speed increase and porosity decreases, the pressure drop of the separator increases. The results indicate that replacing metal foam by porous media is effective and simulating the pressure drop is feasible and effective in a separator with metal foam.

Aircraft pitot tubes are sophisticated instruments designed to detect airflow pressure and relay this information to onboard computers and flight instruments, enabling the calculation of airspeed through the measurement of total-static pressure differences. The formation of ice on aircraft pitot tubes can compromise the acquisition of airspeed data, misguide pilots, and potentially cause catastrophic flight control failures. This article introduces a predictive methodology for identifying critical conditions that lead to icing on aircraft pitot tubes. Utilizing numerical simulation techniques, the methodology calculates the critical conditions for pitot tube icing across cruise flight regimes and atmospheric conditions, resulting in the generation of a critical condition envelope surface. By comparing these critical conditions against actual sensor data, a predictive danger zone can be established, offering an advanced warning system to ensure flight safety.

One of the main issues faced in the operation of a metal foam centrifugal breather is the high pressure drop. This study investigates the pressure drop of a metal foam centrifugal breather. The numerical simulation research method is adopted. The DPM model is used to calculate the two-phase flow field of the metal foam breather, and the porous medium model is used to replace the metal foam at the breather. The resistance caused by the metal foam is replaced by a distributed resistance added to the fluid. The effects of flow rate, rotational speed, porosity, PPI (pores per inch), and temperature on the pressure drop of the breather are analyzed. The results indicate that rotational speed, flow rate, porosity, and PPI significantly influence the resistance of the metal foam centrifugal breather. The resistance of the breather is directly proportional to the rotational speed, flow rate, temperature, and metal foam pore density, and inversely proportional to the porosity. Temperature has a minor impact on the resistance of the metal foam centrifugal breather. Therefore, the metal foam centrifugal breather is more suitable for low-speed operating conditions.

Fan rotor blades are critical components of aeroengines. When an aircraft flies in icing conditions, ice accumulation on the fan surface may lead to periodic shedding. Severe ice shedding can cause mechanical damage to the engine, posing significant safety risks. This study investigates ice accretion on the surface of ROTOR 67 rotor blades and their stress distribution. This paper presents an in-depth analysis of the internal stress distribution of ice layers on the surface of rotating blades under different icing times and rotational speeds, especially the stress concentration of the areas at the contact surface between the ice layer and the blade. This study predicts the stress distribution of ice layers under different working conditions more accurately, which helps to identify potential ice layer fracture risks in advance. Moreover, it integrates the icing process, stress distribution, and shedding mechanism for analysis, providing a comprehensive perspective. It considers the interaction of various environmental factors and operating conditions, offering an in-depth understanding of ice layer behavior under complex working conditions.

Hail absorption test of aeroengine is one of the important components of airworthiness certification. The accurate test data are closely related to the density and mechanical properties of the artificial hail used in airworthiness tests. Through experimental research, this study explores the impact of distilled water, carbonated water and deionized water on the density and mechanical properties of artificial hail. The study addresses the significant differences between the density and mechanical properties of artificial hail and natural hail in existing studies. Based on this, a new method for preparing airworthiness test hail is proposed. The results indicate that artificial hail samples with distilled water as the hail core and carbonated water as the hail shell have densities ranging from 0.87 cm³ to 0.89 cm³. Furthermore, the estimated average maximum compressive strength of samples is 6.538 MPa, with some samples as low as 3.681 MPa. The mechanical properties of this artificial hail are more similar to those of natural hail. This method can more realistically simulate natural hail environments and can be used for the fine design of airworthiness certification criteria.

One of the reliable methods of studying engine icing is to carry out testing in an icing wind tunnel. Due to the operational limitations of test facility, model-size scaling is adopted. An icing scaling test method for the rotating cone is established based on the dimensional analysis coupled with similarity theory and evaluated by considering the rotating effect. Similarity parameters are determined in the following five aspects: flow field similarity, droplet trajectory similarity, water catch similarity, heat balance similarity, and rotating characteristics similarity. Experimental icing tests have been performed at rime and glaze ice conditions to evaluate the scaling method in a closed-loop icing wind tunnel. Results show that the maximum error between the reference and scale ice shapes occurs at the stagnant point. On the areas apart from this, there is a significantly smaller error. Hence, the scaling test method is proven to be effective and reliable and can provide a theoretical basis for parameter selection of the ice wind tunnel tests.