Composite Propeller Research Articles

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.

Numerical and experimental study of the cavitation performance of a composite propeller

Cavitation, which is harmful and unavoidable, has troubled people for a long time and it is urgent to be solved. A composite propeller has the potential ability to improve the cavitation performance because of its distinctive hydro-elastic characteristic, but the related research is limited. In this paper, the cavitation performance of a composite propeller under uniform and non-uniform wake flow is investigated numerically and experimentally. A cavitation coupling simulation method is presented for predicting the cavitation performance of a composite propeller. Cavitation tests are conducted at a cavitation tunnel. The calculated and tested results of cavitation hydrodynamic performance and cavitation patterns are discussed and analyzed. The results show that they are quite consistent, more importantly, cavitation has a significant impact on the hydro-elastic response of a composite propeller.

Damage identification for UAV composite propeller blades based on transmissibility probabilistic distance and attention bidirectional temporal convolutional network

Damage identification of composite propeller blades is critical to the operational safety of unmanned aerial vehicles (UAVs). The transmissibility function (TF) was employed to characterize the damage and its probabilistic distance was used to deal with the uncertainty problem. The damage indicator fusing multiple TFs in a specific frequency band was proposed to detect the blade damage. In addition, to localize the damage in the blade, an attentional bidirectional temporal convolutional network (ABiTCN) model was developed, in which the Squeezeand-Excitation (SE) attention module was introduced to enhance the model’s capability to learn critical features. The proposed method was investigated by numerical and experimental cases. The results showed that the proposed damage indicator has more sensitivity to weak damage and better robustness than the common indicator. The established ABiTCN model predicted the positions of the damages with 91.89 % accuracy, which outperforms other methods in terms of accuracy and convergence speed.

Damage-related imbalance identification for UAV composite propeller blades based on bidirectional temporal convolutional network and a flexible sensing system

Abstract Damage to the composite propeller blades could lead to rotational imbalance, which seriously affects the operational safety of unmanned aerial vehicles (UAVs), therefore, a novel method combining the Teager energy operator (TEO) and bidirectional temporal convolutional network (BiTCN) is proposed for detecting, localizing, and quantifying the damage-related imbalance in the blades. A flexible sensing system that contains Micro electro mechanical sensor accelerometers, signal conditioning, and wireless transmission is integrated with the composite propeller for in-situ signal acquisition of the propeller blades. TEO is applied to demodulate and enhance the pulse compositions in vibration signals and singular value decomposition (SVD) is employed to suppress random noise, resulting in denoised Teager energy spectrums for model input. Temporal convolutional network (TCN) has been widely used in sequence signal modeling because the causal dilated convolution could learn the context information of sequence signals while maintaining the advantages of parallel computing. To fully extract the signal features, BiTCN models are established to learn both the forward and backward signal features. Experimental verification results show that the proposed method detects the existence of imbalance with 100% accuracy, and the accuracies of localization and quantization are 99.65% and 98.61%, respectively, which are much higher than those of the models with the original signal as input. In addition, compared with the other four different algorithms, BiTCN is superior in terms of convergence speed and prediction accuracy.

Acoustic emission monitoring of composite marine propellers in submerged conditions using embedded piezoelectric sensors

Flexible composite marine propellers can aid the marine industry in reducing carbon emissions and underwater radiated noise pollution. The structural integrity of the blades can be assessed using structural health monitoring. One of these methods is the measurement and analysis of damage-induced acoustic emission signals. This paper experimentally investigates the feasibility of using embedded piezoelectric sensors for the measurement of acoustic emissions throughout a submerged flexible composite marine propeller blade. A full-scale glass-fibre reinforced polymer blade has been manufactured with 24 embedded sensors. While suspended in artificial seawater, acoustic emissions were simulated on the blade. The measurements show that the embedded piezoelectric sensors can measure acoustic emissions while the blade is submerged. Further, the distance from source to sensor over which the acoustic emission is measurable was investigated. For a noise level of 40 dB and a source amplitude of 70 dB between 100 and 250 kHz, an average maximum measurable distance of 124 mm was obtained. For higher frequencies, the distance drops and for lower noise levels the distance increases.

A Succinct Review on the Numerical and Experimental Performance Evaluation Techniques for Composite Marine Propellers

A Succinct Review on the Numerical and Experimental Performance Evaluation Techniques for Composite Marine Propellers

Acoustic emission monitoring of composite marine propeller blades using embedded piezoelectric sensors and hydrophones

The marine industry is increasingly considering the use of flexible composite marine propellers for their potential to reduce carbon emissions and underwater radiated noise. Given the early stage of development of flexible composite propellers, there are unknowns on their structural degradation. Structural health monitoring (SHM) can provide additional insight into the occurrence and propagation of degradation in these structures. A passive and lightweight method of SHM is the measurement and processing of acoustic emissions (AE) that are induced by different degradation mechanisms. The current research investigates the measurement of AE signals in composite marine propeller blades using embedded piezoelectric sensors. A full-scale glass-fibre polymer composite propeller blade is suspended in a tank filled with artificial seawater. The propeller blade contains 24 embedded piezoelectric sensors that were installed between laminas during manufacturing. Additionally, the tank includes an array of hydrophones for validation of the results. AE signals are simulated on the blade using underwater pencil lead breaks. The measured AE signals are assessed for their amplitude and frequency content. The results demonstrate the feasibility of measuring AE signals in composite marine propeller blades using embedded piezoelectric sensors and hydrophones.

Numerical analysis of the unsteady cavitation performance and structural characteristics of composite propeller

Abstract The hydrodynamic performance of a composite propeller under cavitation conditions is analyzed considering the bidirectional transient fluid-structure coupling. The structure field and the flow field are calculated using ANSYS Mechanical/CFX and the information is transferred between them by the interface. It indicates the unsteady cavitating flow features in the presence of the wake condition manifest periodic tendencies. Additionally, the hydrodynamic coefficients of the composite propeller display a phase delay. The composite propeller demonstrates decreased volume of cavitation and enhanced efficiency. The bend-twist coupled deformation in the propeller mitigates the effects of cavitation loads on the performance.

Improving the Flexibility of Ship Propellers Additively Manufactured from High-Density Polyethylene/Long Carbon Fiber Composites by Prepreg Coating.

In efforts to achieve the goal of reducing ship emissions in the fight against climate change, reducing fuel consumption by making ships lighter is stated as one of the solutions. In this study, the possibilities of making composite equivalents of propellers, which are the most complex ship elements and traditionally produced from metal materials, are investigated with the advantages of additive manufacturing, which offers a rapid production opportunity for such forms. In this way, a lighter composite propeller and, therefore, a lighter ship will be achieved, and negative environmental impacts, especially harmful emissions, will be reduced. In the study, a 1/14-scale ship propeller was produced through the material extrusion method of additive manufacturing using an HDPE composite containing long carbon fiber with a 15% weight fraction. An attempt to reduce flexibility with an epoxy-carbon fabric prepreg coating was made, as the flexibility has negative effects on the performance of the produced propeller. The propeller tunnel test showed that the applied carbon fabric epoxy prepreg helped to improve the propeller's performance by decreasing the flexibility of the propeller and reducing the deformation at the tips. At the same time, the propeller weight was decreased by 60% compared to its metal counterparts.

Метод чисельного визначення динамічних характеристик лопаті повітряного гвинта з композиційного матеріалу

The subject matter of this article is the dynamic characteristics of a composite propeller blade. Determination of the modes and frequencies of natural vibrations is necessary to predict the dangerous resonance modes of aircraft engines and to identify the most stressed local zones of the blade surface. The goal of this study is to develop a verified method for determining the dynamic characteristics of composite rotor parts of aircraft engines based on the known properties of the structural components of the composite material. A general mathematical statement of the problem of elasticity theory for the analysis of the dynamic characteristics of composite structures is described. A complete system of equations that describes the mechanical state of the body within the framework of the continuum mechanics approach was developed. Geometric modeling of the propeller blades was performed. Modeling and numerical investigation of the natural frequencies and mode shapes of the propeller blade were performed using the finite element method using the ANSYS software package. Based on the results of numerical research of the stressed and deformed state of the propeller blade, the first five natural vibration frequencies and the distribution of the local stress field were determined. The most stressed local zones on the blade surface were determined for each form of natural vibration. The propeller blade model was verified using an experimental study of the first five forms and frequencies of natural blade vibrations. The eigenfrequencies of the blade vibration were experimentally determined using the method of free (natural) vibrations. The resonance method was used to experimentally determine the resonant frequencies and vibration modes of the blade. The distribution of the blade deformation field was investigated using the strain gauge method. The highest error in the verification of numerical and experimental research is 4.11% for the fourth vibration frequency. Conclusions. The scientific novelty of the results obtained is that the effective elastic properties of the composite material for calculations should be determined using the procedure of numerical homogenisation of composite materials of different reinforcement structures by the properties of the matrix and fibers. The method does not require experimental determination of the effective elastic constants for the layers of blade components of different weave architecture patterns.

Design, Analysis and Optimization of Composite Propeller Shaft

Most of the automobiles have Rear wheel drive and front engine installation consists of a transmission shaft. Substitution of conventional metallic (SM45C) Propeller Drive Shaft with the composite (CFRP) structure has many advantages. Composite materials have acquired prominence in the engineering industry due to their remarkable strength-to-weight ratio, corrosion resistance, and adaptability. This paper explores the multifaceted process of designing, analysing, and optimizing composite propeller shafts, with a primary focus on their application in marine and automotive industries, aiming to maximize performance while reducing weight. The design phase initiates by establishing precise requirements, encompassing torque loads, rotational speeds, environmental conditions, and safety factors. Material selection is a pivotal decision point, considering factors like fiber type, resin matrix, and layup orientation. Advanced Finite Element Analysis (FEA) technologies are used to simulate the mechanical behaviour of composite propeller shafts under a variety of operational scenarios, assisting in the identification of stress concentrations. Deformations, as well as key failure modes. The design process is iterative. The feedback from these simulations is used to improve the basic design. The analysis phase stress distribution, torsional vibrations, and dynamic behaviour of the composite propeller shaft. A comprehensive study of various layup configurations and boundary conditions is conducted to assess their impact on structural performance and reliability. Additionally, manufacturing considerations, encompassing fabrication techniques, quality control, and cost-effectiveness, are addressed to ensure practical feasibility. The goal of the optimization phase is to lower the weight of the composite propeller shaft while retaining structural integrity and operational reliability. The optimisation outcomes provide information on the best material mix, layup sequence, and geometric factors that achieve the best balance of weight reduction, greater performance and productivity. The findings from this study contribute substantially to the advancement of composite propeller shaft technology, offering engineers valuable insights into the intricacies of design, analysis, and optimization processes. By harnessing the ability of composite materials effectively, industries can realize significant benefits, including reduced fuel consumption, improved efficiency, and enhanced overall system performance, resulting in more sustainable and competitive products for the maritime and automotive sectors.

Optimal structural design for a certain near-space composite propeller of airship using adaptive region division blending model

Near-space airship is a frontier and hotspot in current military research and development, and the near-space composite propeller is the key technology for its development. In order to obtain higher aerodynamic efficiency at an altitude of 22 km, a certain near-space composite propeller is designed as a long and slender aerodynamic shape with a 10 m diameter, which brings many challenges to the composite structure design. The initial design is obtained by the composite structure variable stiffness design method using based on fixed region division blending model. However, it weighs 23.142 kg, exceeding the required 20 kg. In order to meet the structural design requirements of the propeller, a variable stiffness design method using the adaptive region division blending model is proposed in this paper. Compared with the methods using the fixed region division blending model, this method optimizes region division, stacking thickness and stacking sequence in a single level, considering the coupling effect among them. Through a more refined region division, this method can provide a more optimal design for composite tapered structures. Additionally, to improve the efficiency of optimization subjected to manufacturing constraints, a hierarchical penalty function is proposed to quickly filter out the solutions that do not meet manufacturing constraints. The above methods combined with a Genetic Algorithm (GA) using specific encoding are adopted to optimize the near-space composite propeller. The optimal design of the structure weighs 18.831 kg, with all manufacturing constraints and all structural response constraints being satisfied. Compared with the initial design, the optimal design has a more refined region division, and achieves a weight reduction of 18.6%. This demonstrates that a refined region division can significantly improve the mechanical performance of the composite tapered structure.

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.

Numerical analysis of the performance of a composite marine propeller blade subject to structural blade oscillations

High-fidelity Large Eddy Simulations (LES) are conducted over the oscillating marine propeller blades to investigate the effects of blade oscillation on the unsteady flow behaviour as well as to analyse the performance of the composite marine propeller blades. The accuracy of the results is first verified against the reference experimental results. A nonlinear frequency-domain solution or harmonic solution method is also applied to this study, based on a high-fidelity LES model, in addition to the traditional time-domain solution method to investigate the capabilities of the frequency-domain method in predicting the unsteady flow parameters, vortex generation, and hydrodynamic damping to determine the stability of the propeller blades. Results obtained reveal that the oscillation of the blade has a great impact on the vortex generation process which could impose implications on the performance and structural integrity of the composite marine propeller blades.

Composite material: A review over current development and automotive application

The quantity and quality of studies undertaken to find new applications for the material indicate its importance in the modern world. It used to be accepted wisdom that a design engineer would only employ tried-and-true components, but times have changed. The field of current material engineering would be severely lacking without using composites. Designers of all stripes now have better options for utilizing cheaper, less labour-intensive materials thanks to advancements in composite technology. Composites have several potential applications and are currently employed in some of them. This research describes the process for creating composite propeller shafts and examines their vibrational qualities. This research will look into the results of switching out steel drive shafts for composite ones. Two of the most crucial parts of a composite drive shaft's construction are the shaft itself and the couplings. Critical speed, static torque, and nonlinear isotropic material behaviour are assumed for adhesive joints, but these assumptions are disregarded for metal and a composite shaft. For the design and accompanying analysis, finite element software is used (ANSYS). As a result, the research provides crucial information for developing a composite drive shaft.

The impact of curved-tip propeller geometry on hovering drone performance for air quality monitoring

The success or failure of a drone mission depend on several elements, including the drone’s mass and payload, the surrounding environment, the battery’s state, and the propulsion system’s performance. Several studies have been undertaken addressing the propeller performance of this final component, particularly for fixed-wing or quad copter drones with ducted propellers. However, the shape of propeller blades used on tiny civil drones has not drawn as much attention. In this research work, the performance characteristics of a 10 × 4.7-inch curved tip propeller were explored, with the Advanced Precision Composite drone propeller serving as a design reference. This study seeks an alternative to ducted propellers when mass or size limitations prevent their use. The Computational Fluid Dynamics model was confirmed by comparing simulation results to the experimental propeller data source established by the University of Illinois at Urbana-Champaign, starting with a standard type propeller and using thrust coefficient as the key performance indicator. Moreover, the data analysis for the bended tip propeller replicating the well-established model, revealed the benefits as well as the drawbacks of such propellers on the mission profile and the battery lifespan of a quad copter Unmanned Air Vehicle.

Composite propeller design optimization for cavitation minimization using deep learning-based objective parameter prediction model

Recently, composite propellers have attracted attention as a means of reducing cavitation. To maximize cavitation reduction when using a composite propeller, the design of a composite propeller must be optimized. In this study, deep learning-based prediction models for composite propeller design optimization and design optimization procedures based on these models are proposed. The prediction models are trained using a training dataset consisting of the training input data obtained from a data scan grid, and the training output data include cavitation volume, adaptive deformation, and failure index. To minimize cavitation on a composite propeller, a composite propeller design optimization procedure for propeller geometry and composite lay-up sequence based on the developed prediction models is established. By following the proposed procedure, an optimized composite propeller design that minimizes cavitation volume and adaptive deformation is obtained. The cavitation of the optimized composite propeller is approximately half that of the original propeller. This result verifies the effectiveness of the proposed design optimization procedure based on the developed prediction models.

Designing Composite Adaptive Propeller Blades with Passive Bend-Twist Deformation for Periodic-Load Variations Using Multiple Design Concepts.

Four plausible design concepts are applied together to investigate composite bend-twist propeller-blade designs that show high twisting per bending deflection. The design concepts are first explained on a simplified blade structure with limited unique geometric features to determine generalized principles for applying the considered design concepts. Then, the design concepts are applied to another propeller-blade geometry to obtain a bend-twist propeller-blade design that achieves a specific pitch change under an operational loading condition with a significant periodic-load variation. The final composite propeller design shows several times more bend-twist efficiency than other published bend-twist designs and shows a desirable pitch change during the periodic-load variation when loaded with a one-way fluid-structure-interaction-derived load case. The high pitch change suggests that the design would mitigate undesirable blade effects caused by load variations on the propeller during operation.

Tip clearance influence on hydrodynamic performance and pressure fluctuation of a composite ducted propeller using a two-way FSI method

With the development of advanced materials, composite materials have been studied by researchers over the world to make them more applicable to many applications, especially in the marine industry. As an important component of marine vehicles, propellers have been studied over decades to achieve the goals of increasing hydrodynamic performances and structural properties. However, traditional marine propellers manufactured with metallic materials have many limits. Therefore, the use of composite material to improve the performances of the propeller has become a research hotspot since their great structural performances and material damping properties can improve the comprehensive performance of the propellers such as increased hydrodynamic performances and reduced pressure fluctuation characteristics. The ducted propeller is a typical marine propulsor, which has a tip clearance between the blade tip and the inner face of the duct that can cause a complex fluid flow around the blades and influence the performance of the propeller. In this research, the tip clearance influence on hydrodynamic performance and pressure fluctuation of a composite ducted propeller compared with a metallic equivalent is calculated using a two-way fluid-structure interaction (FSI) method. The results indicate that the use of composite materials with a proper stacking sequence on the ducted propeller blade with a smaller tip clearance size corresponding to GSR = 0.417 can achieve good hydrodynamic properties for the propeller, and it has a significant inhibiting effect on pressure fluctuations on the blade surface.

Experimental evaluation of the use of embedded fiber Bragg gratings to measure steady and unsteady flow-induced marine propeller blade deformation

This paper presents an experimental study that investigates the deformation of a composite propeller blade subjected to a uniform inflow. An array of fiber Bragg grating sensors were embedded inside the blade, allowing for real-time monitoring of strain. Measurements were carried out in the towing tank at Centrale Nantes, France. An original experimental setup was developed to support and fully submerge the blade in the hydrodynamic facility, which reduced the effect of the free surface during testing. The blade, with a root chord of 0.3 m and a span of 0.5 m, was instrumented with embedded fiber Bragg grating (FBG) sensors on both the pressure and suction sides to measure the deformation field. The FBG measurements were dynamically synchronized with a six degree-of-freedom hydrodynamic balance to measure the loads and moments on the blade. Visualizations of the boundary layer regime were observed to determine the flow detachment regions at the surface. The carriage velocities utilized were between 1 and 4m/s and the angle of attack of the blade, based on the zero-lift angle of attack, ranged between 0 to 12∘. After determining the natural frequencies and modes of the blade using laser doppler vibrometry, the forces and deformations were investigated under hydrodynamic flow for both averaged and unsteady data. For averaged results, a good correlation is observed between the lift force and deformations, which demonstrates the accuracy of the measurement system. The fluid–structure interaction dynamic is analyzed using the frequency spectra of drag, lift, pitching moment, and deformations. The interaction between Strouhal frequencies of vortex shedding resulting from flow detachments at the blade surface is identified with the flow visualization, and the modal response of the blade is demonstrated.