Aerodynamic Properties Research Articles

Development and characterization of nintedanib inhalable powders as a potential pulmonary fibrosis treatment

Nintedanib is an orally administered intracellular tyrosine kinase inhibitor approved for idiopathic pulmonary fibrosis. Differently from oral treatment, dry powder inhalers (DPIs) can deliver a higher drug concentration at the target site, reducing doses and systemic side effects. The aim of this work was to develop dry powders of Nintedanib with properties suitable for inhalation therapy. Particles were prepared by spray drying the drug alone (3–5% w/v) or with appropriate excipients, from different hydroalcoholic solutions i.e., water/ethanol (7/3 v/v) or water/isopropyl alcohol (from 7/3 v/v to 5/5 v/v) mixtures. The powders obtained were characterized in terms of process yield, particle size distribution, morphology, density and aerodynamic properties. The results indicated that leucine improved the aerosol performance of the powders, increasing the value of the fine particle fraction (FPF) from 47.9 % in the drug only batches to 73.1 % using 5 % w/w leucine. This improvement was attributed to the ability of the amino acid to change both the surface area of the particles and the fluidity of the powder. Therefore, this study demonstrated the possibility of developing dry powder of Nintedanib for local administration in the lungs for the treatment of pulmonary fibrosis.

Targeted delivery of the metastasis-specific tumour homing TMTP1 peptide to non-small-cell lung cancer (NSCLC) using inhalable hybrid nano-assemblies.

Lung cancer is one of the most fatal malignancies, with the highest death rate (∼19%), and the NSCLC type accounts for ∼85% of lung cancers. In the search for new treatments, antimicrobial peptides have received much attention due to their propensity for selective destruction of cancer cells. In the current study, we evaluated the efficacy of the metastasis-specific tumour-homing-TMTP1 peptide against lung cancer using inhalable hybrid nano-assemblies of the PEG-PLGA copolymer as a carrier for pulmonary delivery which was assessed for aerodynamic and physicochemical properties, along with the peptide-release profile, physical stability, cellular uptake and biocompatibility, generation of reactive oxygen species, cell migration, autophagic flux, and apoptotic cell death in A549 lung cancer cells. Optimization of inhaled dose, lung retention, and efficacy studies was conducted to evaluate the formulation in an NNK (nicotine-derived nitrosamine ketone) induced tumour-bearing lung cancer murine model. After inhalation, the formulation with nano-scale physiognomies showed good lung deposition, retention, and metabolic stability. The inhalable nano-assemblies have shown enhanced generation of reactive oxygen species with increased autophagy flux and apoptotic cell death. Pre-clinical animal trials show substantial tumour regression by inhalable TMTP1-based nano-formulation with limited side effects. Our results on metastasis targeting and tumour-homing peptide TMTP1 demonstrate its effective tumour targeting and tumour-killing efficacy and provide a reference for the development of new therapeutics for NSCLC.

Moisture dependent physical, mechanical, and aerodynamic properties of Simarouba glauca seed: A potential tree born oilseed

AbstractThe present study investigates the moisture dependence of the physical, mechanical and aerodynamic properties of Simarouba seeds within the moisture range of 9.24‐22.46% d.b. The length, width and thickness significantly increased from 19.43 to 22.71 mm, 11.52 to 13.88 mm and 9.79 to 11.34 mm respectively. Our findings showed significant effect of moisture content on the one thousand unit mass, bulk density, true density, and porosity which varied in the range of 1050.41g and 1204.7g, 638.88 to 503.88 kg∙m−3, 999.57 to 970.26 kg∙m−3 and 36.08% to 48.06%. Moisture content was found to have positive effect on the angle of repose terminal velocity and static coefficient of friction for all surfaces studied. A decreasing trend in rupture force and increasing trend in deformation with moisture content was also observed. The understanding of these properties as per the present study would be useful for designing post‐harvest processing equipment and storage of Simarouba seeds.Practical applicationsSimarouba glauca, D.C. is an evergreen potential tree born oilseed tree with high scope for biodiesel and edible oil production. The oilseed is presently underutilized due to lack of availability of suitable processing equipment. The findings of the study provide a comprehensive design database related to engineering properties of Simarouba seeds. The predictive models developed in this study can be used to assess the seed properties at any given moisture content range. The enrichment of database would serve as a guide for agricultural engineers, and food processors in the design and development of relevant post‐harvest handling, and processing equipment for Simarouba seeds. This may further lead to promotion of Simarouba processing as a promising enterprise in rural India.

Determination of Optimal Technological Parameters for Sorting Wheat Grains in Chambers of Different Constructions

In order to extend grain’s storage time and ensure its quality, it is necessary to sort and clean it. The aim of this study was to justify the rational shape of the sorting chamber and the optimal technological parameters for the sorting of wheat grains in airflow. This study used newly designed grain sorting chambers with constant, widening, and narrowing cross-sections for the airflow sorting of “Skagen” wheat grain. The aerodynamic properties of wheat grains were investigated when moisture was at 14 ± 2.0%. The grain flow rate in the chambers varied from 4 to 12 kg min−1 every 2 kg min−1. In addition, the airflow velocity varied from 8 to 12 m s−1 every 1 m s−1. The tilt angle of the constant cross-section camera was increased to 5°. Experimental studies have determined a terminal airflow velocity of 11.53 m s−1 for wheat grains. At the terminal airflow velocity, the grain flight coefficient was obtained to be about 0.074. These studies showed that the narrowing chamber is preferable for lower grain flow rates compared to the constant cross-section of the chamber. The widening chamber requires a lower airflow velocity to achieve the same performance and quality as the other chambers.

Physical and aerodynamic properties of date palm pollen grains

The present study was designed to determine the effect of four moisture content levels (4, 5, 6, and 7 %) on the physical and aerodynamic properties of date palm pollen grain (DPP). The physical properties of DPP included pollen length (L), width (w), thickness (T), projected area (Ap), geometric mean diameter (dg), mass (m), sphericity (S), and bulk density (ρp). It was observed that the moisture content did not significantly influence the physical properties of the DPP. The aerodynamic properties of DPP included the terminal velocity (Vt), drag coefficient (Dc), drag force (Df), and Reynolds number (Re). The pollen Reynolds number (Re) is significant at different pollen grain moisture content, and regression models were developed in the form of polynomial and exponential relationships. Also, the 3rd order polynomial relationship was found between Re and Dc. The results showed that the average values of Vt, Dc, Df, and Re were about 0.6 m s-1, (0.38 to 0.45), 1.09E-11 N, and (0.29 to 0.42), respectively. The results of this study will be helpful in the performance of date palm pollination machines.

Flow around an Aircraft Model—Comparison between Hydrodynamic Tunnel Tests and Computational Fluid Dynamics Simulations

This paper presents a comparative analysis of the results obtained using the computational fluid dynamic method and a hydrodynamic tunnel. The aerodynamic properties of the General Dynamics F-111 Aardvark aircraft were subjected to both qualitative and quantitative assessment. In both cases, the same geometric model of the aircraft was used. For the hydrodynamic tunnel tests, the model was 3D printed, while for the CFD simulations, the geometry was imported into ANSYS Fluent 2021 R2 software. During quantitative studies, aerodynamic characteristics, including the coefficients of lift, drag, and pitching moment for the aircraft, were determined over a wide range of angles of attack. In turn, flow field images and pathline visualization of the vortex were obtained following qualitative studies. The comparative analysis showed that high consistency between the simulation and experimental results was achieved.

Design of a robust controller for the VEGA TVC using the L1-Adaptive Control

The purpose of this study is to Design of a robust controller for the VEGA TVC using the L1-Adaptive Control. The performance of the system with an L1 adaptive controller has been compared with that of a classical controller. The L1 adaptive controller optimization is an efficient as well as an effective approach for the design of a robust controller. The L1 adaptive controller ensures the robustness of the system against uncertainties, noise, and disturbances[10]. In a launch vehicle parameters like mass, thrust, and aerodynamic properties are time-varying. Due to the time-varying nature of these parameters gain scheduling is necessary with the classical control design methods otherwise the closed-loop system might become unstable for some values of these parameters. This procedure is costly and has no robustness. In addition to this, there are external disturbances also which can make the control system unstable. This is the reason why robust control is necessary. There is a trade-off between achievable performance and robustness. So, we need to compromise between required performance and robustness as per the requirement.

Numerical Modelling of Static Aeroelastic Deformations of Slender Wing in Aerodynamic Design

Abstract The article presents the validation of two methods for analyzing the aerodynamic properties of the aircraft wing concerning aeroelastic effects. The first method is based on low-cost computational models (Euler–Bernoulli Beam Model and Vortex Lattice Method [VLM]). Its primary objective is to estimate the wing’s deformation early in the design stages and during the automatic optimization process. The second one is a method that uses solutions of unsteady Navier–Stokes equations (URANS). This method suits early design, particularly for unconventional designs or flight conditions exceeding lowfidelity method limits. The coupling of the flow and structural models was done by Radial Basis Functions implemented as a user-defined module in the ANSYS Fluent solver. The structural model has variants for linear and nonlinear wing deformations. Features enhancing applicability for real-life applications, such as the definition of deformable and nondeformable mesh zones with smooth transition between them, have been included in this method. A rectangular wing of a high-altitude long-endurance (HALE) aeroplane, built based on the NACA 0012 profile, was used to validate both methods. The resulting deflections and twists of the wing have been compared with reference data for the linear and nonlinear variants of the model.

Numerical analysis of aerodynamic and structure characteristics of an autonomous unmanned flying car for high-rise building rescue operations in urban area

Using numerical commercial software, this article presents a type of autonomous unmanned flying car capable of saving people in burning high-rise buildings in urban areas. This kind of flying vehicle is maneuverable and fast, and it has the ability to anchor to the building balconies to receive people in distress. Initial, a computational simulation is performed to investigate the aerodynamic properties of the propeller without and with a guard ring. A full-scale model evaluation based on Buckingham-Pi theory is then performed to evaluate the aerodynamic and structural characteristics of the proposal. Numerical simulation results show that the proposed design is feasible.

Aerodynamic Analysis of Mathematically Modelled Propeller for Small UAV Using CFD in Different Temperature Conditions

Unmanned aerial vehicle (UAV) usage has witnessed a significant rise owing to its cost-effectiveness and versatile applications. However, the design techniques for UAV propellers, encompassing aerodynamic and structural analysis, have received limited attention from researchers. A well-designed propeller can effectively reduce battery consumption and enhance overall efficiency. This study focuses on mathematically designed propellers and compares them with advanced precision composite (APC) Slow Flyer propeller blades in terms of thrust coefficients, power coefficients, and efficiency. The investigation includes the utilization of tetrahedron meshing in simulations, employing the standard k–ω (k–omega) model. To evaluate the accuracy of the blade element theory (BET) in predicting thrust, the simulation data is compared with BET results. Furthermore, the study encompasses experimental testing to validate the simulation findings. The findings demonstrate that the mathematically modelled propeller outperforms the APC Slow Flyer propeller across all ranges of revolutions per minute (rpm). When comparing the results of both methods, BET exhibits an error difference of 10 % in higher rpm ranges, but this error diminishes as the rpm decreases. This study contributes a novel design technique for modelling propellers using mathematical formulas and provides a comprehensive comparison of their aerodynamic properties with existing propellers, utilizing both BET and computational fluid dynamics (CFD) methods, along with experimental validation.

Development of a new inhaled swellable microsphere system for the dual delivery of naringenin-loaded solid lipid nanoparticles and doxofylline for the treatment of asthma

This study developed a new dual delivery system of naringenin (NRG), a polyphenol, and doxofylline (DOX), a xanthine derivative, as an inhaled microsphere system. In this system, NRG has been first loaded into glyceryl tristearate-based solid lipid nanoparticles (NRG SLN), which were further loaded with DOX into swellable chitosan-tripolyphosphate-based microspheres (NRG SLN DOX sMS). The system was characterised based on particle size, PDI, zeta potential, surface morphology (SEM, AFM, and TEM), solid-state and chemical properties (XRD, IR, and NMR), aerodynamic parameters, drug loading, entrapment efficiency and in vitro drug release study. The optimised NRG SLN DOX sMS exhibited particle size, zeta potential, and PDI of 2.1 µm, 31.2 mV, and 0.310, respectively; a drug entrapment efficiency > 79%; a drug loading efficiency > 13%; cumulative drug releases of about 78% for DOX and 72% for NRG after 6 and 12 hours, respectively; good swelling and desirable aerodynamic properties. In addition, in vivo studies conducted in mice, a murine model of asthma showed significant reductions in serum bicarbonate and eosinophil counts and improvement in respiratory flow rate, tidal volume, and bronchial wall lining compared with the asthmatic control group. Overall, this novel inhalable dual-delivery system may represent a good alternative for the effective treatment of asthma.

Evaluation of the effects of storage conditions on spray-dried siRNA-LNPs before and after subsequent drying

In an ideal world, pharmaceutical drugs would have infinite shelf life, no susceptibility to degradation, chemical reactions or loss of efficacy. In reality, these processes occur, however, making it desirable to extend a drugs’ shelf life. Nucleic acid-based drugs are most commonly stored as aqueous suspension where they are vulnerable to microbial growth and degradation processes. Drying procedures, such as lyophilization and spray drying, help to reduce the products’ residual moisture while increasing the products’ shelf life and stability. The present study was designed to evaluate 90 days of storage of spray-dried siRNA-lipid nanoparticles (LNPs) at 4 °C and 25 °C. An updated Onpattro® composition modified with a positively charged helper lipid was used as the LNP carrier system. In an attempt to further reduce the residual moisture of our previously reported formulations, all LNP samples were subjected to a secondary drying step in the spray drying tower for 20 min. The measurement of physicochemical properties of spray-dried and subsequently dried LNPs resulted in sizes of 180 nm, PDI values of 0.1–0.15 and zeta potentials of + 3 mV. Spray drying resulted in residual moisture levels of 3.6–4 % and was reduced by subsequent drying to 2.8–3.1 %. Aerodynamic properties after storage showed discrepancies depending on the storage conditions. MMADs remained at 2.8 µm when stored at 4 °C, whereas an increase to 5 µm at 25 °C was observed. Subsequent drying led to sizes of 3.6–3.8 µm, independent of the storage conditions. Spray-dried LNPs maintained bioactivity resulting in > 95 % protein downregulation and confirming the lack of cytotoxic effects in a lung adenocarcinoma cell line. Furthermore, the spray-dried and subsequently dried LNPs stored for 3 months at 4 °C and 25 °C achieved up to 50 % gene silencing of the house-keeping gene GAPDH after deposition on the mucus layer of Calu-3 cells. This study confirms the stability of spray-dried and subsequently dried LNPs over at least 90 days at 4 °C and 25 °C emphasizing the potential of dry powder inhalation of RNA-loaded LNPs as a therapy option for pulmonary diseases.

Winter wheat seed treatment

Problem statement. The article presents the results of research on the peculiarities of post-harvest and pre-sowing winter wheat seed treatment using a modern technological line.
 Methods. Laboratory, measuring and weighing, mathematical and statistical.
 Results. Pre-sowing seed treatment is carried out in three stages: primary cleaning of small and large impurities and small seeds of the main crop, pre-sowing preparation — calibration of seeds by size, aerodynamic properties and specific weight in order to improve seed quality and final treatment with insecticides, fungicides and other substances for protection seddlings from pests and diseases. The technological line for the preparation of seeds of agricultural crops, which was installed at the Research Agricultural Production Institute of the Institute of Plant Physiology and Genetics of the National Academy of Sciences of Ukraine, provided a yield of conditioned winter wheat seeds of 84–92.4%, depending on varietal characteristics. Seed yield differed by variety. The highest yield was obtained by pre-sowing seed treatment of the ‘Darynka Kyivska’ variety — 92.4%, and the lowest with Horodnytsia’ and ‘Novosmuhlianka’ varieties — 84.0%. Conclusions. Pre-sowing seed treatment on the technological line with a small waste, which was an average of 13.3% for varieties, ensured obtaining of five batches of seeds, which in terms of germination rate exceeded the requirements of the current standard by 4%, as well as an increase in the 1000 kernel weight to 44.0 grams.

Improvement in Inhalation Properties of Theophylline and Levofloxacin by Co-Amorphization and Enhancement in Its Stability by Addition of Amino Acid as a Third Component.

Co-amorphous systems are amorphous formulations stabilized by the miscible dispersion of small molecules. This study aimed to design a stable co-amorphous system for the co-delivery of two drugs to the lungs as an inhaled formulation. Theophylline (THE) and levofloxacin (LEV) were used as model drugs for treating lung infection with inflammation. Leucine (LEU) or tryptophan (TRP) was employed as the third component to improve the inhalation properties. The co-amorphous system containing THE and LEV in an equal molar ratio was successfully prepared via spray drying where reduction of the particle size and change to the spherical morphology were observed. The addition of LEU or TRP at a one-tenth molar ratio to THE-LEV did not affect the formation of the co-amorphous system, but only TRP acted as an antiplasticizer. The Fourier transform infrared spectroscopy spectra revealed intermolecular interactions between THE and LEV in the co-amorphous system that were retained after the addition of LEU or TRP. The co-amorphous THE-LEV system exhibited better in vitro aerodynamic performance than a physical mixture of these compounds and permitted the simultaneous delivery of both drugs in various stages. The co-amorphous THE-LEV system crystallized at 40 °C, and this crystallization was not prevented by LEU. However, THE-LEV-TRP maintained its amorphous state for 1 month. Thus, TRP can act as a third component to improve the physical stability of the co-amorphous THE-LEV system, while maintaining the enhanced aerodynamic properties.

Project technologies in teaching natural sciences

This article reveals the peculiarities of the science teacher's activity in organizing the work of high school students on projects of various types. The relevance of this issue is related to the fact that the project method is one of the most effective methods for increasing the cognitive activity of high school students as well as the formation of key and subject competencies in them, including practical skills that are important in further activities. Different types of projects that can be offered to students in the process of studying natural sciences have been considered. They are classified by the direction and the method of implementation (informational, practice-oriented, research), by the term (short-term, medium-term and long-term) and the form of implementation (individual, group and individual-group projects). The functions of the teacher and students at each stage of the implementation of the educational project have been defined, which include: organizational-preparatory, search, final, resulting, final stages. The roles and functions of students that they can perform in the process of group work on the project have been classified (organizational, motivational, executive, control). Within the framework of the practical part of the research, examples of the application of the project method in the educational process of high school have been given. In particular, the peculiarities of the organization of students’ work during the implementation of an individual informational project in chemistry on the topic: «Methods of disposal of PET-products», a group practical-oriented project from the integrated course «Natural Sciences» on the topic: «Research on the compliance of the school menu with the energy needs of children of different ages» and an individual group research project on physics on the topic: «Aerodynamic properties of paper airplanes» have been considered. The emphasis is placed on the fact that the use of project technologies in science lessons allows to increase the motivation of students to study and also contributes to their academic success. At the same time, it requires high professional training of the teacher to apply the project method in educational activities. Therefore, the direction of further research is the formation of future science teachers’ readiness to use project technologies in the teaching of natural sciences at institutions of general secondary education.

Thermal performance and energy cost of Korean multispan greenhouse energy-saving screens

Protected agricultural system such as a greenhouse cultivation is increasingly replacing traditional farming systems. Nonetheless, high energy demand in greenhouse farming requires innovative technologies through the use of climate screens to ensure sustainable production. Thus, this study developed a novel methodology for examining the energy retention capacity and economic effectiveness of greenhouse climate screen materials using their thermophysical, radiometric and aerodynamic properties in TRNSYS software. The TRNSYS model was developed to determine the energy consumption, which was validated using a multi-span Venlo-type experimental greenhouse (Yeoju, South Korea). Further analyses on energy saving capacity of different screens and the equivalent energy costs were performed. The results from this research showed that among the fifteen investigated screens, the ensemble screen (M3) saved 34.09 kWh.m−2 of annual energy, equivalent to 60 % of the heating energy demand, and energy cost of 4490.26 Korean won. m−2. Further, the results revealed that the climate screens with multi-layer, thermoreflective, low longwave transmissivity, impermeable and aluminized strips or surface characteristics and features have a considerable impact on reducing greenhouse energy use and desirable for high energy-saving. This research has demonstrated that the techniques and methods utilised can investigate all the types of covering and thermal screens used in greenhouse.

Robust Constrained Multi-Objective Guidance of Supersonic Transport Landing Using Evolutionary Algorithm and Polynomial Chaos

Landing of supersonic transport (SST) suffers from a large uncertainty due to its highly sensitive aerodynamic properties in the subsonic domain, as well as the wind gusts around runways. At the vehicle design stage, a landing trajectory optimization under wind uncertainty in a multi-objective solution space is desired to explore the possible trade-off in its key flight performance metrics. The proposed algorithm solves this robust constrained multi-objective optimal control problem by integrating non-intrusive polynomial chaos expansion into a constrained evolutionary algorithm. The computationally tractable optimization is made possible through the conversion of a probabilistic problem into an equivalent deterministic representation while maintaining a form of the multi-objective problem. The generated guidance trajectories achieve a significant reduction of the uncertainty in their terminal states with a marginal modification in the control history of the deterministic solutions, validating the importance of the consideration of robustness in trajectory optimization.

Experimental studies of airliner aerodynamic characteristics at overcritical angles of attack

PurposeThe main purpose of this study was to determine the basic aerodynamic characteristics of the airliner Tu-154M at the wide range of the overcritical angles of attack and sideslip angles, i.e. α = −900° ÷ 900° and β = −900° ÷ 900°.Design/methodology/approachWind tunnel tests of the Tu-154M aircraft model at the scale 1:20 were performed in a low-speed wind tunnel T-3 by using a six-component internal aerodynamic balance. Several model configurations were also investigated.FindingsThe results of the presented studies showed that at the wide range of the overcritical angles of attack and sideslip angles, i.e. α = −900° ÷ 900° and β = −900° ÷ 900°, the Tu-154M aircraft flap deflection affected the values of the drag and lift coefficients and generally had no major effect on the values of the side force and pitching moment coefficients.Research limitations/implicationsThe model vibration which was the result of flow separation at high angles of attack was the wind tunnel test limitation.Practical implicationsStudies of the airliner aerodynamic characteristics at the wide range of the overcritical angles of attack and sideslip angles allow assessment of the aircraft aerodynamic properties during possible unexpected situations when the passenger aircraft is found to have gone beyond the conventional flight envelope.Social implicationsThere are no social implications of this study to report.Originality/valueThe presented wind tunnel test results of the airliner aerodynamic characteristics at overcritical angles of attack and sideslip angles is an original contribution to the existing not-too-extensive database available in the literature.

Tailoring Dry Microparticles for Pulmonary Drug Delivery: Ultrasonic Spray Freeze-Drying with Mannitol and Salbutamol Sulphate

Spray freeze-drying has emerged as a valid alternative to traditional spray drying to produce therapeutic dry microparticles. In particular, the spherical shape and high porosity of spray freeze-dried microparticles make them suitable for pulmonary drug delivery through dry powder inhalers. However, an appropriate particle size and fine particle fraction are required to guarantee lung deposition. This study used ultrasonic spray freeze-drying to generate dry microparticles composed of mannitol either alone or added with the bronchodilator salbutamol sulphate. The influence of the solid concentration and the feed flow rate on the particle size, morphology, surface area, porosity, and crystallinity was investigated. Growing particle size was observed, increasing the concentration and feed flow rate. Similarly, the addition of the drug led to a larger particle size and surface area. The in vitro simulation of drug deposition highlighted the dependence of the aerodynamic properties on the solid concentration and feed flow rate. Due to the lower density and particle geometric size, the highest fine particle fraction (26%) and smallest mass median aerodynamic diameter (4.4 μm) were reached at the lowest solid concentration and feed flow rate.

Aerodynamics and Aeroacoustics of Leading Edge Serration in Low-Speed Axial Fans With Forward Skewed Blades

Abstract Low-speed axial fans must comply with a wide number of standards and normative restrictions, often related to the maximum noise emission levels. Among the noise control techniques in axial fans, skewed fan blades and leading edge serrations have been found to be effective in leading edge noise control, which represents one of the dominant phenomena in axial fan broadband emissions. However, these solutions are usually applied separately, and literature is scarce on systematic studies on the coupling of the two modifications. In this work, a campaign of experimental measurements was conducted on unskewed and forward-skewed axial fan blades with and without leading-edge serrations. The tests were performed in undisturbed inflow conditions. The flow field and the turbulence characteristics were measured using three-dimensional hot-wire anemometry. The suction-side sound radiation of the fans was measured with microphones in an anechoic chamber. In addition, the rotating beamforming method was used to localize the sound sources at the axial fans. It was found that, regardless of the blade skew, the leading edge serrations lead to a reduction of the sound pressure level, whereby the aerodynamic properties of the fan decrease. At the same operating points, which were achieved by adjusting the rotational speed, the sound radiation through the leading edge serrations could be reduced at high-volume flows. This effect was more pronounced with the unskewed rotor, which indicates that the positive effect of the serrations is reduced by the already optimized shape of the forward skewed fan blade. Based on the experimental results, the four geometries were further considered for numerical investigations to understand how the serrations affect the fan operations and the overall aerodynamics of the rotor. All four geometries were simulated with RANS approach at the duty point to derive a flow survey and better understand the dynamics driven by serrations and blade skewing.