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Abstract
The development of aircraft composite propeller blade is necessarily required because recently changing metal propeller to composite propeller is a global tendency due to the improvement of composite manufacture technique and good characteristics of composite materials. The complicated calculation was required at the stress analysis and the design because the aircraft propeller was in curved and twisted structure. Especially, in the case of composite propeller, the analytic method was almost impossible on account of anisotropic material properties. Therefore, the numerical analysis method must be used for the solution of the problem. In this study, structural design and analysis of the propeller blade for turboprop aircraft, which will be a high speed transportation system for the next generation, was performed. The propeller of turboprop shall have high strength to get the thrust to fly at high speed. The high stiffness and strength carbon/epoxy composite material was used for the major structure and skin-spar-foam sandwich structural type was adopted for improvement of lightness. As a design procedure for the present study, firstly the structural design load was estimated through investigation on aerodynamic load and then flanges of spars from major bending loads and the skin from shear loads were preliminarily sized using the netting rule. In order to investigate the structural safety and stability, stress analysis was performed by finite element analysis code MSC. NASTRAN. Finally, it is investigated that designed blade have high efficiency and structural safety to analyze of aerodynamic and structural design results.
... Therefore, the rotor blade structure must be designed properly and strong enough to ensure flight safety. Recently, many researchers have studied its different aspects, such as aerodynamics [8][9][10][11][12][13], structural analysis/design [14][15][16][17], and fabrication of drone/aircraft propellers [18][19][20][21][22][23][24][25][26][27][28][29]. For instance, Kutty and Rajendran used the Fluent CFD solver to determine the aerodynamic loads for a small and slow flyer propeller blade [11]. ...
... The blade core failure is also considered in the failure analysis of the composite sandwich blade. The Tsai-Wu criterion of Equation (14) together with the SOLID185 elements will be used to identify the initiation of core material failure. Once the failure index at any point in a core element exceeds 1, the initial Young's modulus E c of the core element will be replaced by αE c where α is a small number much less than 1. ...
The development of light composite rotor blades with acceptable load carrying capacity is an essential issue to be dealt with in the design of relatively large copter-type drones. In this paper, a method is established to determine the quasi-static blade load carrying capacity which is vital to drone reliability. The proposed method, which provides a systematic procedure to determine blade load carrying capacity, consists of three parts, namely, a procedure to determine the distributed quasi-static blade aerodynamic load via the Blade Element Momentum (BEM) approach, a finite element-based failure analysis method to identify the actual blade failure mode, and an optimization method to determine the actual blade load carrying capacity. The experimental failure characteristics (failure mode, failure thrust, failure location) of two types of composite sandwich rotor blades with different skin lamination arrangements have been used to verify the accuracy of the theoretical results obtained using the proposed load carrying capacity determination method. The skin lamination arrangement for attaining the optimal blade-specific load carrying capacity and the blade incipient rotational speed for safe drone operation has been determined using the proposed method.
... Seeni [16] used a fluid-structure interaction (FSI) coupling to analyze the structural behavior of a commercially available small UAV propeller. Kong et al. [17] used commercial codes MSC. NASTRAN and PASTRAN to perform a structural analysis of an aerodynamically designed composite propeller obtaining good agreement between calculated data and experimental results. ...
The widespread use of unmanned aerial vehicles (UAVs) has gained significant importance given their low cost and range of possible applications. Nevertheless, design methodologies integrating aerodynamic and structural evaluations for UAV propellers have not been widely explored. A proper design of UAV propellers provides compelling energy savings, and the selection of structurally adequate blades ensures UAV integrity. This work presents a methodology for the aerodynamic design of propellers using parametric and high-fidelity tools coupled with a structural evaluation scheme using FEM. For this aim, different propeller configurations were determined using BEMT and MIL approaches. Furthermore, a baseline airframe and usual operating conditions for monitoring tasks were selected and evaluated throughout several optimized propeller configurations. The design obtained through the two-dimensional aforesaid approach is evaluated using numerical simulation, coupling the aerodynamic loads with the structural design through FSI in ANSYS 18. Subsequent aerodynamic evaluation revealed congruence between BEMT and CFD results, with a 9% maximum percentage error between results. Moreover, the findings of the studied case scenarios showed an improvement in thrust generation capabilities for a 1.48 m diameter 3 bladed propeller, with an 80% efficiency. Results for the structural assessment indicated acceptable stress concentrations for all configurations at the design point and an overall better structural performance for a 0.99 m diameter 3 bladed propeller. To summarize, the main contribution of this work is a design methodology tailored for UAV propellers able to predict their performance and optimal configurations using a fast and accurate enough calculation scheme for preliminary design stage.
... The flowing fluid is considered as air at 20°C and the flow is steady. The boundary conditions are shown in Table 2 which are the assumptions based on the past authors' work [15,[48][49][50]. ...
The commercially available unmanned aerial vehicles are not good enough for search and rescue flight at high altitudes. This is because as the altitude increases, the density of air decreases which affects the thrust generation of the UAV. The objective of this research work is to design thrust optimized blade for an altitude range of 3,000–5,000 m with a density of air 0.7364 kg/m3, respectively, and perform thrust analysis. The property of aluminum alloy 1,060 being lightweight is chosen for designing and testing of blade. The blade element theory-based design and analysis code was developed, and user-friendly aerodynamic inputs were used to obtain the desired outputs. The geometry designed for an altitude range of 3,000-5,000 m faced the total stress of 6.0 MPa which was at 70% of the blade span. This stress is within the limit of yield strength of the aluminum alloy, 28 MPa. The modal analysis shows the first natural frequency occurs at around 12,000 RPM which is safe for operating the blade at 0-5,000 RPM. Experimental analysis of the blade gave a thrust of 0.92 N at 2,697 RPM at 1,400 m. The analytical solution for thrust with the same conditions was 1.7 N with 85.6% efficiency. The validation of experimental results has been done by the CFD analysis. The CFD analysis was performed in ANSYS CFX which gave a thrust value of 2.27 N for the same boundary conditions. Thus, the blade designed for high altitude SAR UAV is structurally safe to operate in 0-5,000 RPM range, and its use in search missions could save many lives in the Himalayas.
... Changduk Kong et al [20,21] and Hyunbum Park [24] designed propeller blade which was made up carbon/epoxy fabric skin-spar and urethane foam core sandwich. The aerodynamic and stress analysis was carried using finite element analysis (FEA), the bird strike analysis was also conducted using ANSYS. ...
Jet engines require special materials that can withstand the demanding environments imposed on the various components and sections, so selection of materials is primary requirement during design of jet engine components. This paper is the study of various materials and their applicability for different components of jet engine for the purpose of enhancing the performance, reliability and durability. Review of materials for different types of jet engines such as turbojet engine, turboprop engine, turbofan engine, turboshaft engine, ramjet and scramjet engine is presented. This paper overviews the properties and materials used for different types of jet engines and can be used for further researchers in the field of jet engine materials.
An extensive aeroacoustic and aerodynamic investigation of an innovative regional turboprop aircraft has been carried out experimentally and numerically under the framework of two research projects funded by the European Union through the CleanSky Research Programme. Experimental tests have been performed in the RUAG Large Subsonic Wind Tunnel in Switzerland and CFD results have been validated against the experimental data. The A/C high-lift performance, stability and control derivatives, aerodynamic noise sources, and low-noise solutions for high-lift devices, have been investigated under representative conditions in cruise, take-off, and landing configurations. The aerodynamic and aeroacoustic investigation has been carried out parametrically, in terms of several reference quantities, including the propellers’ thrust and rpm, the speed of the air-flow, the incidence angle of the aircraft and the position of the microphone array used for the acoustic investigation. The present paper gives an overview of relevant results obtained for selected aircraft configurations which have been tested in the wind tunnel and analyzed through CFD simulations. The focus lies on the overall aerodynamic characterization and on the noise sources identification carried out using standard beamforming techniques.
This paper presents research on diagnostic parameters for monitoring conditions of a light aircraft engine blade made of composite materials (CM) in flight. This study covers the modal parameters investigation of the blades in the frequency range of 30 to 60 Hz. Using the Doppler Effect the vibration response between the used blades and a new blade was compared. The used blades demonstrated a fourfold increase in amplitude of resonant vibration in the first bending mode. The amplitude growth of the first bending mode resonant vibration can be used as a diagnostic sign of emerging defects. The ease of amplitude and frequency analysis of a blade resonant vibration in flight conditions will allow researchers to develop an express-control device for technical condition analysis of CM blades while in air.
This present study provides the structural design and analysis of main wing, horizontal tail and control surface of a small scale WIG (Wing-in-Ground Effect) craft which has been developed as a future high speed maritime transportation system of Korea. Weight saving as well as structural stability could be achieved by using the skin–spar–foam sandwich and carbon/epoxy composite material. Through sequential design modifications and numerical structural analysis using commercial FEM code PATRAN/NASTRAN, the final design structural features to meet the final design goal such as the system target weight, structural safety and stability were obtained. In addition, joint structures such as insert bolts for joining the wing with the fuselage and lugs for joining the control surface to the wing were designed by considering easy assembling as well as more than 20 years service life.
Marine and air screw propellers are considered in terms of theoretical
hydrodynamics as developed by Joukowsky, Prandtl, and Betz. Attention is
given to the flow around wings of finite span where spanwise flow exists
and where lift and the bound vorticity must all go smoothly to zero at
the wing tips. The concept of a trailing vortex sheet made up of
infinitesimal line vortexes roughly aligned with the direction of flight
is discussed in this regard. Also considered is induced velocity, which
tends to convect the sheet downward at every stage in the roll-up
process, the vortex theory of propellers and the Betz-Prandtl
circulation distribution. The performance of the Gossamer Albatross and
of a pedal-driven biplane called the Chrysalis are also discussed.
By reducing the diameter of a transonic propeller at constant rotational speed a significant noise reduction can be achieved. The number of blades is increased to retain the thrust. For a given design quality a loss in efficiency due to the increase propeller loading can be expected. This has to be compensated by a good design for minimum induced loss and use of optimised airfoils such as the DLR propeller airfoil family. After comparison of a blade element method, a panel and an Euler method, the blade element method was chosen for the aerodynamic design and the panel method was chosen for the aeroacoustic numbers and different numbers of blades. Tip shape studies based on the inviscid panel method exhibit little effects on noise but do effect efficiency.
The application of advanced technologies shows the potential for significant improvement in the fuel efficiency and operating costs of future transport aircraft envisioned for operation in the 1990s time period. One of the more promising advanced technologies is embodied in an advanced turboprop concept originated by Hamilton Standard and NASA and known as the propfan. The propfan concept features a highly loaded multibladed, variable pitch propeller geared to a high pressure ratio gas turbine engine. The blades have high sweepback and advanced airfoil sections to achieve 80 percent propulsive efficiency at M=0.80 cruise speed. Aircraft system studies have shown improvements in fuel efficiency of 15–20 percent for propfan advanced transport aircraft as compared to equivalent turbofan transports. Beginning with the Lockheed C-130 and Electra turboprop aircraft, this paper presents an overview of the evolution of propfan aircraft design concepts and system studies. These system studies include possible civil and military transport applications and data on the performance, community and far-field noise characteristics and operating costs of propfan aircraft design concepts. NASA Aircraft Energy Efficiency (ACEE) program propfan projects with industry are reviewed with respect to system studies of propfan aircraft and recommended flight development programs.
The development of unsteady aerodynamic analysis with computational fluid dynamics important for investigating the aeroelastic characteristics of rotors made of advanced composite materials. The purpose of the present analysis is to establish an aeroelastic model useful for the preliminary design of advanced turbo propellers. An unsteady aerodynamic model of high subsonic cascade airfoils, including sweep effects and finite span effects, is combined with a structural dynamic model for composite pretwisted propeller blades to produce an aeroelastic analysis tool. The p-k modal flutter analyses for the SR-3 propeller model (made of graphite/epoxy) were conducted. They revealed that suitable combinations of the fiber orientation can eliminate flutter without any weight penalties or strength penalties and that the flutter velocity is found to be sensitive to the interblade phase angle as well as the fiber orientation. These results indicate the effectiveness of aeroelastic tailoring for advanced turbo propellers and also the usefulness of the present analysis.
This paper presents the application of the CANARI flow solver to the computation of unsteady effects in the aerodynamic interaction of a high speed propeller with the aircraft. The method is first validated on the APIAN isolated propeller test case by comparison with experiment at M=0.7. The method is then applied to the time accurate 3D Euler computation of a generic transport aircraft at M=0.68. Analysis of the results shows significant unsteady effects both on the propeller forces and on the wing aerodynamic flows, by comparison with steady computations.
This paper is about the development of a high speed propeller noise prediction code at Langley Research Center. The code utilizes two recent acoustic formulations in the time domain for subsonic and supersonic sources. The selection of appropriate formulation is automatic in the code. The structure and capabilities of the code are discussed. Grid size study for accuracy and speed of execution on a computer is also presented. The code is tested against an earlier Langley code. Considerable increase in accuracy and speed of execution are observed. Some examples of noise prediction of a high speed propeller for which acoustic test data are available are given. A brisk derivation of formulations used is given in Appendix 1.