Flutter Analysis Of A Scaled Model Of An Eagle 150b/Ac Wing

An investigation of the problem of the flutter condition of an Eagle 150B aircraft wing is undertaken. The research is largely devoted to investigating the adequacy of the ideal flutter theory that has been employed to predict flutter boundary for such wing. A series of panel flutter experiment carried out in UPM 1m × 1m wind tunnel at Mach number up to 0.132 are described in detail. Furthermore, an extensive parametric computational analysis has been conducted to improve flutter condition by reconfiguring the wing design specification. For experimental analysis, the ground test which includes static and dynamic tests of the wind model has been performed followed by the wind tunnel testing. The data gathered from the wind tunnel testing is analyzed using the logarithmic decrement method so that the flutter speed can be predicted. The wing model mounting system test rig has been designed and developed together with the data acquisition system which is used for data collection. In order to validate the experimental technique, wind tunnel testing using three different types of materials for rectangular flat plate has been conducted. The types of materials used are aluminum 6061, mild steel and stainless steel. The agreement between experimental technique and computational analysis is acceptable since the error of difference is less than 6 percent. MSC. Patran and Nastran software have been used to predict the flutter condition since it has the capability to carry out the aeroelasticity analysis of the actual wing and wing model. The PK-method and aerodynamic doublet lattice methods were selected for this analysis as it provides the eigenvalue solutions in the form of the V-g and V-f graphs. Validation of the computational analysis with two existing published results is performed to ensure the results are reliable. The parametric study produced the results on the effects of the mass, altitude, span length, stiffness and center of gravity position against the flutter speed condition. This research work may conclude that both techniques are reliable to investigate flutter speed since the validation results showed a good agreement. It was also found that through extensive parametric study, several suggestions have been made to reconfigure the wing in order to improve the flutter condition

New metal fuselage section arrangement minimize assembly time

The development approach of the aircraft industry is briefly explained. Analyzing innovation attempts from 1950s to present showed the introduction of the coil fuselage concept and how it developed into the integral frames and panels concept currently pursued. The novel design is then proposed to bridge the gap between impractical novel ideas and industry needs which put cost first. The new structure is to require minimum time for assembly. It is also to eliminate the need for advanced manufacturing, usually suggested by innovative ideas in the field. The new structure is based on common aluminum alloy sheets to minimize variance from the conventional semi-monocoque structure manufacturing requirements. Whereas numerical comparison with the conventional structure showed up to 15% weight savings and about 45% decrease within inquired maximum stress could be achieved. The stress reduction was suggested to be a result of the new structure’s arrangement homogeneity

LCO flutter analysis on coir pressed mat fibre/epoxy composites plate

The effects of aspect ratio and fiber-epoxy weight ratio of coir fibre/epoxy composite wing idealized as flat plate on flutter speed were preliminary studied in this current research to investigate the aeroelastic response on natural fiber composite material. The usage of natural material such as coir fiber reinforced composite might become possible solutions in future since it offers lower weight, cost reduction, and preservation of the environment factor compared to presence structures like conventional glass or carbon fiber as the reinforcement for composites. For this work, the analysis of coir fiber on aeroelastic problem will be preliminary investigated to establish related data to be served, especially in the aerospace research areas. The research began with the existing raw untreated coir fiber, which was in the form of pressed mat and originally in random oriented fiber forms, were set in the composite preparation process by simple hand-lay-up and compression moulding method under the room temperature and also controlled pressure conditions. Specimen with different aspect ratios (5, 6 and 7) with 25% wt fiber reinforcement composite was installed in the wind tunnel for subsonic experimental aeroelastic test. The result shows that the plates with lower aspect ratio have higher flutter speed

Derivation of strategic solution space for product redesign planning

Planning for product redesign could become an overwhelming task due to possible change effects propagation phenomenon, particularly for complex product designs. However, it is observed that the solution space during redesign planning is normally constrained by product manufacturers. This leads to the notion that substantial amount of redesign efforts could be saved if designers are assisted to strategically define the solution space for their product redesign. This paper proposes a structured methodology to achieve this goal. Potential benefits of the proposed methodology have been demonstrated by the presented aircraft redesign case study

A review on the micro energy harvester in Structural Health Monitoring (SHM) of biocomposite material for Vertical Axis Wind Turbine (VAWT) system: a Malaysia perspective

The usage of wind energy as a form of renewable energy is becoming increasingly popular year by year. This technology has been applied widely in several regions in the world and already reached maturity in terms of technology, infrastructure and cost competitiveness. The performance of the wind turbine system depends upon factors such as design, aerodynamic performance and material selection. Thus, Structural Health Monitoring (SHM) has become crucial in evaluating the performance of wind turbine in real time. Furthermore, the application of smart material in SHM can be utilized as micro energy harvester as well. Nonetheless, the application of SHM in Malaysia׳s climate for wind turbine is still premature, especially in the approach biocomposites material towards its blade system. Several issues are highlighted in this paper such as Vertical Axis Wind Turbine (VAWT), biocomposites material selection and the issue in the micro energy harvester as well. The issues are discussed and compared with the recent finding in this review. Several recommendations are suggested for future studies in benefiting the Malaysian especially on the application of wind energy to promote better green technology for tomorrow

Alternative numerical validation methodology for short-term development projects

Virtual prototyping has been increasingly taking over the process of sole physical tests. Companies are reporting up to 80% reduction in errors when using virtual tests through the design process. Conventional numerical validation methodology however, is not as beneficial for short-term projects because any new numerical scenario has to be validated before being used. Although during the conceptual stage, relative values can be sufficient. The alternative methodology proposed also uses realistic loads. It comprise applying these loads on a functioning structure to verify them. The modified version of the structure is then relatively validated by being tested under these verified loads. Thus, bypassing the physical tests requirement. Aerodynamic loads are acquired from simulating the Gulfstream IV-SP forward fuselage during climbing, cruising and landing. Mechanical loads are acquired from estimating structural weight and impact load during landing. In total, three finite element models were created. Autodesk softwares were used to perform CFD and FEA. Only greater loads were applied during FEA. Results simplified neglected cruising data for having lowest values. Comparing estimated weights of functional and modified structures showed a possible 15% weight savings. While the FEA results showed a promising 45% less inquired stress within the modified structure

Effects of different cross-section shapes on bending and weight of harvesting pole by using finite element analysis

Harvesting pole is a main requirement in harvesting activity that involves tall trees. A long pole always has problems with bending and weight. Study on the effect of cross-section shapes on bending and weight may give some information about the best design for harvesting pole. Laboratory testing is expensive and time consuming. Finite element analysis using computer software is the best method and cost less. A total of six designs of pole cross-section were tested using Pro-Mechanica software for obtaining their bending/deflection. The six shapes are circular, hexagon, octagon, decagon, icosagon and ellipse. A total of five testings were implemented, that consist of combination of three pole conditions, loaded/unloaded, end/middle constrained and same/different weight. The analyses results show that the circular cross-section shape is the strongest shape to resist bending. Ellipse cross-section shape has different value of bending depends on the orientation. Final evaluation shows circular and icosagon were the best cross-section of harvesting pole

Conceptual product design methodology through functional analysis

Due to high competitive nature of todays product market, it is essential for conceptual design architecture solution to be derived faster while still maintaining a certain level of innovation to differentiate it from other competing products. This can be a handful task for the development of complex product designs with the current geometrical-based approaches due to plethora of possible physical alternatives to be considered. The search for product design architecture solutions from its functional requirements is more effective as the functional space is comparatively smaller than the physical search space. This allows the design and development effort to be more focused and saves time and resources. With this notion, there is a driving motivation to adapt the functional approach into the conceptual design process to exploit some of its benefits. In this paper, a methodology to derive the product architecture solution from functional approach is discussed and proposed

Freestream Velocity Correction in Narrow Channels / Helmey Ramdhaney Mohd Saiah ...[et al.]

An experimental study was done on the effect of boundary layer development to freestream velocity in a narrow channel tunnel. Fundamental boundary layer theories were applied in quantifying and estimating the changes in the freestream velocity along the tunnel. It was found that the measured and the estimated freestream velocities were in good agreement. The increase in the freestream velocity was found due to the boundary layer blockage effect. The experimental results demonstrated that the corrected freestream velocity had negligible effect on the boundary layer analysis but it nevertheless proved to be a significant effect on correlating the flat plate heat transfer experiments

Enhanced attitude control structure for small satellites with reaction wheels

Purpose: This paper aims to describe a design enhancement for the satellite attitude control system using reaction wheels, and the wheel momentum unloading using magnetorquers. Design/methodology/approach: The proportional – integral–derivative-controller and active force control (AFC) schemes are developed together with their governing equations for closed loop system of attitude control. Four numerical simulations were carried out using the Matlab – Simulink™ software and results were compared. Findings: From the results, it is evident that the attitude accuracies for roll–pitch–yaw axes have improved significantly through the proportional – derivative (PD) – AFC controller for the attitude control and the wheel momentum can be well maintained during the momentum unloading scheme. The results show that the AFC has a high potential to be implemented in the satellite attitude control system. Practical implications: Using AFC, the actual disturbance torque is considered totally rejected by the system without having to have any direct prior knowledge on the actual disturbance itself. Originality/value: The results demonstrate the satellite attitude control using reaction wheel is enhanced by PD–AFC attitude controller