Propeller Design Research Articles

Numerical Study of the Cavitation Performance of an Ice-Blocked Propeller Considering the Free Surface Effect

Propeller cavitation performance can be predicted based on model tests or simulations. However, the cavitation performance of an ice-blocked propeller near the free surface differs from that of a propeller in the cavitation tunnel. Therefore, research on the cavitation performance simulation of propellers near the free surface holds crucial scientific significance. In this study, a coupled model was established using Computational Fluid Dynamics (CFD) and the Volume of Fluid (VOF) coupling method. The CFD-VOF model weighted the overlapping grids and simulated the cavitation performance of an ice-blocked propeller using various immersion depths, cavitation numbers, and advance coefficients. The propeller inflow ahead of the propeller and the wake field behind it were controlled to accurately obtain the propeller cavitation performance. Moreover, a comparison was conducted between the cavitation tunnel test results and the numerical simulation results at various immersion depths. When the immersion depth was at a distance of 1D, the effect of the free surface on the propeller cavitation performance became significant. When the immersion depth was at a distance of 9D, the average errors between the numerical simulation and the model test data were within 10%. This study analyzed the cavitation performance of ice-blocked propellers near the free surface and provided valuable insights for the design of ice-class propellers.

Optimization of Quadcopter Propeller Aerodynamics Using Blade Element and Vortex Theory

The optimization of quadcopter propeller aerodynamics is crucial for enhancing the efficiency and stability of unmanned aerial vehicles (UAVs), especially in their increasing applications across various sectors, including humanitarian relief and delivery services. This study focuses on optimizing quadcopter propeller performance using Blade Element Theory and Glauert Vortex Theory to analyze the aerodynamic properties and predict thrust generation accurately. Experimental methods, including wind tunnel testing and static thrust measurements, were used to validate the theoretical models. The results indicate a close correlation between theoretical predictions and experimental data, providing insights into improving propeller efficiency and mitigating aerodynamic losses. By understanding the propeller characteristics, this research contributes to the development of advanced drone propulsion systems with enhanced thrust, reduced drag, and better overall flight performance. The findings also highlight the impact of environmental factors such as turbulence and blade geometry on quadcopter stability, pointing toward areas for further improvement in propeller design. This paper serves as a valuable resource for drone hobbyists, engineers, and researchers seeking to enhance UAV performance through optimized propeller aerodynamics.

A unified cross-series marine propeller design method based on machine learning

Propeller design diagrams, like Bp-δ diagram, are widely applied in ship propeller design. However, different propeller series use various selection approaches, so comparisons between designs are only possible after individual candidates are chosen.This paper proposes a unified approach based on machine learning to allow efficient comparison and facilitate the selection of the optimal propeller amongst the available propeller series. The process starts by compiling propeller series data to generate a comprehensive dataset on propeller performance. This dataset is then used to train an Artificial Neural Network (ANN) model, which accurately predicts open-water propeller performance. Optimization techniques are applied to maximize propeller efficiency based on the specific needs of the vessel, while ensuring compliance with cavitation and noise constraints for safety. The model's accuracy is validated using data from the KRISO Container Ship (KCS), demonstrating the prediction's reliability. The method is then applied to select both open and ducted propellers for a variety of ship types to meet specific operational requirements. Ultimately, the optimized results are ranked by efficiency, offering an organized set of options for selecting the most suitable propeller. This approach eliminates the need for manual dataset correlation, significantly improving the efficacy of generating an outperforming initial design.

Design Method for Low-Ice-Class Propellers Based on Multi-Objective Optimization

The objective of this paper was to establish a comprehensive methodology for the optimized design of propellers for ice-class vessels, aiming to enhance hydrodynamic efficiency while ensuring structural integrity. This paper begins by introducing a novel approach for calculating blade stress, which takes into account both extreme ice loads and hydrodynamic loads, to be utilized in the propeller strength design process. Subsequently, a backpropagation (BP) neural network model was developed based on the data obtained from B-series propeller charts and integrated with a genetic algorithm to achieve a preliminary optimized design of the propeller’s hydrodynamic performance. To illustrate the application of this methodology, a case study of an ice-breaking tug propeller design is presented, detailing the optimization design process, including the preliminary, intermediate, and final design stages. The study also addresses key aspects such as geometric parameterization, the selection of optimization variables, the implementation of optimization algorithms, and the balance of multi-objective trade-offs. The proposed design approach can serve as a valuable reference for the practical engineering design of propellers for ice-class vessels, providing a systematic framework for achieving optimal performance in challenging operating conditions.

Structural design of a polymer matrix composite ship propeller

This work presents the structural design of a propeller, with its profile established using the OpenProp software for a 5 m long competition catamaran at a speed of 5.5 m/s. The materials selected using the Ashby method were polymer matrix composites, and the chosen manufacturing method was vacuum bagging. The determination of the stacking sequence was initially done using panel theory and the macromechanics of composite materials. The stacking sequence was then optimized using the finite element method with Abaqus CAE. Experimental validation was conducted through instrumented cantilever bending tests on both specimens and the blade. The finite element results showed errors of less than 5% compared to the experimental measurements, thus validating the simulations and allowing the blade to be designed with static safety factors greater than eight under operational service conditions.

Single-Point and Multipoint Design of Propellers for Electric-Powered General Aviation

Single-Point and Multipoint Design of Propellers for Electric-Powered General Aviation

Investigation of The Fatigue Behavior of Gyrocopter Propellers Produced From 6061 T6 Aluminium Alloy

In the aviation sector, the production of propeller-driven aircraft is being accelerated due to the increase in passenger numbers, the possibility of transportation for shorter distances, and the reduction in costs in aircraft designs. Gyrocopter vehicles, which have recently begun to be used in aviation, have significant potential in the near future. The demand for these air vehicles in the aviation sector is growing due to their ability to operate in relatively short ranges, their low operational and maintenance costs. Generally, the systems that most significantly reduce costs in these aircraft are propellers. The technological advancements in material science have facilitated innovative solutions in the design and manufacturing of propellers from a wide range of materials. The combination of nanotechnology and materials science has been achieved alongside ongoing innovations in these two evolving technologies. In this study, samples of propellers produced from 6061 T6 Aluminium Alloy, were produced with a special extrusion model and were then subjected to fatigue, tensile, and hardness tests. The mechanical standards of the produced propellers were examined to determine whether the desired flight configurations could be achieved.

Shape considerations for the design of propellers with trailing edge serrations

Noise reductions due to trailing edge serrations of several representative unmanned air vehicle propellers are calculated using a low-order methodology based on RANS simulations coupled with an extension of Ayton’s model proposed by Li and Lee, which provides a heuristic three-dimensional model for finite span applicable to rotor blades. The latter model is validated in the limit of zero serration amplitude against Amiet’s and Schlinker and Amiet’s models, finding good agreement at high frequencies for both airfoils and rotating blade elements. Similar good validation results are obtained for finite serrations by comparing with experiments achieved on the Controlled Diffusion airfoil at Université de Sherbrooke, and with calculations for a serrated blade element by Tian and Lyu. The coupled methodology is then validated both aerodynamically and acoustically with ISAE measurements for a representative drone propeller at different rotational speeds. The corresponding serrated model is then used to calculate noise reductions caused by different shapes. The square wave serration is shown to outperform the sawtooth and sinusoidal shapes for all frequencies and observer angles for small propeller blades typically used for drones. Yet, for larger chord blades typically used for ducted fans, combinations of sawtooth and sinusoidal serrations provide better noise reductions.

Review of diver propulsion vehicle: A review

The ocean serves as a vital arena for resource exploitation, scientific inquiry, and strategic endeavors. Among the array of underwater propulsion technologies, diver propulsion vehicles (DPVs) stand out for their exceptional integration, concealability, and maneuverability. They hold a pivotal role in both marine scientific exploration and military operations beneath the waves, thus carrying significant research implications. However, the existing literature on DPVs remains limited, lacking comprehensive examinations of their design processes and parameters. This review systematically surveys and assesses the current landscape of DPV development and research. Three key facets—propeller design, performance assessment, and equipment engineering—are scrutinized and analyzed. By consolidating essential data from ongoing studies, this review offers valuable insights. Additionally, it forecasts potential directions and emerging focal points in the evolution of underwater propulsion for frogmen, drawing from current advancements. The objective is to furnish foundational data to support the design and study of frogman underwater propulsion systems, thereby advancing engineering applications in this domain.

Fluid-Solid Coupling Analysis of the Propeller and Optimization of Boss Cap Fin Parameters

In order to ensure the accuracy of propeller modelling and hydrodynamic performance prediction, first of all, compared with atlas modelling and OpenProp modelling, it is pointed out that the characteristics of the blade model established by PropCad are more complete. Secondly, through the analysis and discussion of the computational domain distribution, grid independence verification and turbulence model, the CFD calculation model is established systematically. Thirdly, the hydrodynamic analysis of AU5-80 propeller is carried out under different advance ratios, and the simulation results are in good agreement with the open water test data. The accuracy of CFD calculation model is proved. Then, the fluid-solid coupling analysis of the propeller is performed, and it is verified that the stress field of the propeller meets the material strength requirement. It provides support for the further optimization design of propeller structure. Finally, through the design and analysis of the PBCF propeller, some optimization parameters of the PBCF are obtained. Because the PBCF can diffuse and weaken the hub vortex, the propeller thrust, and efficiency are improved.

Fully resolved simulations of micro-unit composite fuel in hydroxyl-terminated polybutadiene (HTPB): Al@AP

Micro-unit composite fuel (Al@AP) is a promising strategy for achieving stable and efficient combustion, due to its reduced pressure dependency and ability to prevent agglomeration. This research focuses on the heat and mass transfer as well as the reaction mechanism within the Al@AP structure through molecular modeling. The direct contact between the metal fuel and oxidizer leads to an immediate redox reaction at the corresponding interface, facilitating the diffusion of oxygen atoms from surrounding AP molecules into the Al particles. Heat is transferred from the Al particles to the surrounding oxidizer, instead of inward heat transfer from the AP-HTPB interface as observed in the conventional Al/AP composite. This novel assembly method significantly accelerates the reaction rate, more than doubling that of the conventional Al/AP composite. Moreover, the research explores combustion behavior at diverse pressure conditions (condensed phase vs. vacuum), revealing pressure’s minimal impact on the rapid burning stage primarily driven by diffusion mechanism. Under vacuum, reaction products propel burning Al within gas flow, transitioning to surface reactions on Al particles with gaseous products. Regarding agglomerations, the coalescence of two burning Al droplets is observed to form a larger product owing to the reduced distances within AP particle. The Al droplets are almost consumed before coalescence due to the rapid combustion, resulting in no negative impact on the Al combustion. The above findings highlight the unique features of micro-unit composite fuel in the application of solid propellants, and serve as an atomistic guide for propellant manufacturing and design.

Investigating Propellers for Drone Applications: Analyzing Varied Designs and Characteristics

The importance of drones has evidently increased in various aspects of daily life, such as defense, agriculture, disaster management, and more. Drone propellers are crucial for generating the lift and propulsion necessary for steady flight. Efficient propeller design is critical for maximizing flight time and maneuverability in drones. We are currently investigating the impact of different propeller designs on drone performance. Our research focuses on optimizing propeller characteristics to ensure optimal propulsion and overall functionality. By testing three airfoil designs and systematically varying the angle of attack and pitch, we aim to understand how these changes influence the propeller's efficiency and effectiveness. The CFD-based analysis primarily evaluates parameters such as the lift-to-drag ratio and RPM to determine the most suitable design for drone operations. Through extensive analysis and data collection, the study seeks to identify settings that balance performance metrics, ultimately enhancing the drone's functionality. Based on insights from the analysis, various iterations and refinements have been carried out to draw informed conclusions about the most effective propeller design for drone applications.

Molecular dynamics study on the physical compatibility of SEBS/plasticizer blend systems.

Thermoplastic elastomer styrene-ethylene-butylene-styrene block copolymer (SEBS) has excellent mechanical properties and aging resistance, so it has good application prospects in thermoplastic solid propellants. The selection of plasticizer is one of the keys to the formulation design of thermoplastic solid propellant. The compatibility of the plasticizer with the polymer determines the plasticizer's ability to plasticize the polymer's molecular chain segments. Herein, the compatibility of four plasticizers with SEBS was investigated, and the results declared that the order of compatibility between SEBS and the four plasticizers is SEBS/WO > SEBS/DOS > SEBS/DEP > SEBS/TA. Physical compatibility of SEBS binder with plasticizer triacetin (TA), diethyl phthalate (DEP), dioctyl sebacate (DOS), and 26# industrial white oil (WO) was simulated using molecular dynamics (MD) method via Materials Studio 8.0, and the simulation results were verified experimentally. The results showed that the compatibility of SEBS with these plasticizers can be comprehensively evaluated by analyzing solubility parameters, radial distribution functions, and blend miscibility simulations.

A novel multi-fidelity optimization framework for high-altitude propellers

A novel optimization methodology is presented for optimizing high-altitude propellers operating in the lower stratosphere. The proposed methodology combines a Bayesian optimization approach for most design variables and Vortex Theory for the optimization of twist distribution and rotational velocity. For the Bayesian optimization part of the problem, a multi-fidelity approach is employed with three levels of modeling fidelity. The considered fidelity levels, from lower to higher, are: Vortex Theory, and 3D Reynolds-Averaged Navier-Stokes (RANS) with the use of γ−Reθ transition model, converged with first-order upwind, and second-order upwind for the momentum equations. Additionally, the optimization problem involves two objectives: maximizing the cruise efficiency and minimizing the total volume of the propeller. To enhance the performance of multi-fidelity, multi-objective (MFMO) acquisition functions, a novel algorithm is proposed. The proposed optimization methodology demonstrates its effectiveness in generating several high-performing propeller designs and proves to be more efficient than an equivalent problem formulation relying solely on Bayesian optimization. Post-processing of optimization data reveals new design variable bounds that correspond to more efficient blade shapes. These findings provide insights into some important geometric features of high-altitude propellers and establish guidelines for future optimization efforts within the specified thrust and power consumption ranges. Finally, simulations of the best-performing designs across a range of advance ratios and altitudes confirm their high performance in various operating conditions.

THE AIRCRAFT ENGINE PROPELLER MAIN CHARACTERISTICS DETERMINATION IMPROVED METHOD

An improved method of the fixed and variable pitch propeller aerodynamic characteristics determining that based on the vortex theory is presented. It is shown that the design of propellers has it`s peculiarities, it does not take into account a number of factors that affect the propeller operation to one or another degree. This actualized the special purpose unmanned aerial vehicles engines propellers aerodynamic characteristics calculating methodology improvement. Since the use of the propeller profiles performances in the design requires the air compressibility correction introduction already after the selection of the propeller, that complicates the design, therefore the mathematical model of the variable-pitch propeller working process has been improved based on the profile model with the correct consideration of the Mach and Reynolds numbers influence on the aerodynamic characteristics of the air screw. This advantage of the developed airfoil model allows the design and verification of a subsonic propeller for ground and flight operations. Methods of design and verification calculations of propeller blades are presented. Verification of the improved methodology was carried out by comparing calculated data with known experimental data. The reliability of the improved aircraft engine propeller main performances determination methodology is substantiated by the correct application of the numerical and experimental methods of aerodynamics, the consistency of theoretical provisions with experimental data. The satisfactory coincidence of the calculated data obtained by the improved method of the engine propeller main performances determination allowed us to draw a conclusion concerning its efficiency. The improved technique for the main performances of an aircraft engine propeller determination does not require knowledge on the propeller profiles aerodynamic characteristics from which the blade is drawn, since these characteristics are calculated based on known geometric data, taking into account the Mach and Reynolds numbers. This allows you to design and build a subsonic propeller of both fixed pitch and variable pitch.

Study on simulation method of propeller cavitation

Abstract With the continuous improvement of EEDI requirements and high fuel prices, people have higher and higher requirements for the efficiency of merchant propellers, but the efficiency of propellers is limited by cavitation, so it is one of the difficult problems in engineering to quickly evaluate the cavitation performance of propellers. The cavitation performance of the propeller in a viscous uniform flow field is calculated and studied by using computational fluid dynamics commercial software, and the cavitation distribution on the blade surface of the DTMB 4381 propeller under specific working conditions is simulated to study the influence mechanism of cavitation performance. It provides an important guiding direction for the optimal design of propellers and the reduction of ship energy consumption.

Kriging Surrogate-based Optimization for Shape Design of Thin Electric Propeller

Kriging Surrogate-based Optimization for Shape Design of Thin Electric Propeller

Numerical Aerodynamic and Aeroacoustic Analysis of Toroidal Propeller Designs

Drones have a major drawback which prevents them from being used extensively - the excessive noise they produce. This article presents an optimization process of aerodynamic noise reduction for a novel design called the Toroidal Propeller, which consists of two blades looping joined in a manner where the end of one blade arches back into the other, has been designed by the Aerospace Propulsion Systems (APSs) research team at School of Mechanical Engineering, Hanoi University of Science and Technology. In addition, four toroidal propellers with different curved shapes (pitch) and Number of Blades (NOB) are considered. The goal of this research is to evaluate the effects of modifying the geometry design of the Toroidal Propeller on the intensity of blade tip vortex and aerodynamic flow characteristics passing through the blade. The ultimate goal is to decrease blade tip vortex and turbulence produced by the blade, which can help estimate the sound pressure level and minimize it without causing significant performance losses. Based on the outcome results, the models of the four geometry studies are compared in terms of Acoustic Power Level (APL), Surface Acoustic Power Level (SAPL), Thrust, Torque, and Power. In general, the propeller model with NOB of 3 provides the most optimal efficiency in terms of both Thrust and APL. At the output cross-section, the APL dropped from nearly 139 dB to 121 dB, while thrust increased from almost 6.2N to 8.7N compared to the first version of the Toroidal Propeller model.

Impacts of regular head waves on thrust deduction at model self-propulsion point

The results obtained from the self-propulsion simulations using Computational Fluid Dynamics (CFD) in the current study, for a ship free to heave, pitch and surge with the means of a weak spring system, are combined with the formerly executed CFD results of the bare hull and propeller open water simulations to investigate the impacts of regular head waves on the propeller-hull interactions in comparison to calm water, at the self-propulsion point of the model. Despite a rather significant dependency of the nominal wake on the wave conditions, the Taylor wake fraction remains almost unchanged in different studied waves which is around 12% lower than the calm water value. The thrust deduction factor in waves is reduced (12.8%–26.1%) in comparison to the calm water value. The change of thrust deduction factor is found to be associated with the boundary layer contraction/expansion and vortical structure dynamics, originating from the wave orbital velocities as well as the significant shaft vertical motions and accelerations that resulted in a modified propeller action, and consequently diminished suction effect on the aft ship. The altered thrust deduction factor and wake fraction in waves in comparison to calm water underlines the significance of waves on the propulsive factors and propeller design.

Characteristic Property of Combustion and Internal Ballistics of Triple-Based Propellant according to Particle Size of RDX

The important factors in the design of the gun propellant are impetus, flame temperature and pressure. In this paper, we considered a nitrocellulose based propellant composition that replaced sensitive NG(Nitroglycerin) with RDX(Cyclotrimethylenetrinitramine) and DEGDN(Diethylene glycol dinitrate) which high energy and low sensitivity. Particle size and content of RDX are the two main factors that affect the burning stability of RDX-based propellants. Among them, the characteristics of the propellant according to the particle size of RDX were confirmed. The relative combustion rate(R.Q., Relative Quickness) of the propellant changed according to the RDX particle size, and internal ballistics of properties of propellant were also varied. The particle size of RDX can be confirmed as a major factor in the combustion and internal ballistics characteristics of the propellant.