Due to the increase in the number of vehicles, transportation management is achieved through the construction of bridges. This article discusses the vibrational effect in the design of bridges. In the structural design of the bridges proper planning is necessary, as gusts may occur, leading to aeroelastic instabilities. In this article a typical bridge is designed using the design software CATIA and a numerical simulation using analysis software ANSYS. Further, the aeroelastic phenomenon involved in coupling of Fluid Structure Interaction is discussed. The results of Mode shape show vortex-induced vibrations which can lead to Flutter.

Purpose The purpose of this paper is to analyse an actual representation of ice accretions, which are important during the certification process. Design/methodology/approach Ice accretion experiments are conducted in a low-speed subsonic wind tunnel testing facility to evaluate the influence of various ice shapes around the airfoil sections. Ice accumulation changes the shapes of local airfoil sections and thereby affects the aerodynamic performance characteristics of the considered NACA 23012 profile. The ice profiles are impregnated using balsa wood with glace, horn and mixed ice accretion cases for the detailed experimental investigation. Findings Computational fluid dynamics analysis is done to compute the influence of different ice shapes on the aerodynamic coefficients (Cl and Cd) while ice accretion occurs at the leading edge of the airfoil sections. It is observed that the Cl and Cd modified immediately more than 40% as compared to the clean wing configuration. In the same fashion, the skin friction coefficient also abruptly changes for different ice shapes that have the potential to induce flutter at the critical speed of the airplane. The computational solutions are further validated through wind tunnel experiments and recent literature concerning certification for flight in icing conditions. Social implications The ice accretion study on the aerodynamic surfaces can also be extended for wind turbine blades installed at different cold regions around the globe. Further, the propeller icing influences the entire rotorcraft aerodynamics at low temperature conditions and the findings of this study are strongly connected with such problems. Originality/value The aerodynamic characteristics of the baseline airfoil are greatly affected by the ice accretion problem. Although flight through icing condition endures for a short duration, the takeoff path and decision speed are determined based on airplane drag as per federal aviation regulations. Hence, the proposed study is focussed on a cost-effective approach to predict the effect of ice accretion to achieve optimum performance.

Tunnels have very severe air quality constraints that typically require good ventilation system. The process of removing air from any space by mechanical means is known as evacuation. Evacuation of exhaust and smoke in case of fire emergencies is very necessary to bring in fresh air as it leads to pressure and temperature build up which causes discomfort to the passengers travelling especially in long tunnels. Generally, in longitudinal ventilation, a jet blower fan enclosed in a cylindrical casing is used for ventilation. These jet fans accelerate the air by imparting it an impulse in the desired direction. The main aim is to optimize the design and replace the jet blower fan cylindrical enclosure by a CD Nozzle. The suction fan along with rotor is exactly placed at the throat of the nozzle. The modeling is done using CATIA V5 software and CFD flow and modal analysis is carried out using ANSYS V 15.0. Various parameters like pressure, temperature, density, humidity and mass flow rate of air are measured and compared with the conventional model by experimentation and the results are validated.

In an Aerospace industry, reduction of mass is having a greater significance. In this paper the main objective is to reduce the mass of the structure and without getting effected to system parameters like deflections and stresses on the members. Structure is chosen from an existing fighter aircraft and it is generated by a high level of literature study. Modelling is done using a coordinate data of aerofoils and systematic approach of twist angle of structure. The basic model is created in modelling software Pro-E and it is parameterised in analytical software Analytical parametric design language (APDL). Parametric code is developed for optimization study which is an input source code contains all design variables, constraints and objectives. Design variables are number of ribs and Spars and the specific Constraints are considered on the response of the structure such as equivalent stress at the root and deflection of the structure at the tip of the structure. Load cases are calculated and which is analysed to meet the stiffness criteria and strength requirement of the structure. The initial finite analysis is carried out using FEM tool ANSYS and the results are well within the bounds. In order to satisfy the ultimate objective is minimising the mass of structure, using optimization techniques the initial solution is coupled with optimization software Visual DOC. The model is virtually having several designs in the constructive domain space. Two methods are used for optimization i. e., Modified method of feasible directions and Broydon-Fletcher-Goldfrab-Shanno (BFGS). These methods work on gradients calculations in Optimization. This optimization method uses forward finite difference calculations to obtain a numerical estimation of required gradients. By this approach objective is achieved, design variables are concluded and the structural constrains are within the threshold.

A numerical study was undertaken to study the effect of the span wise injection on the performance of a 3D wing at a velocity of 15 m/s and angle of attack of 6°, 8°, and 10°. A baseline configuration along with injection at tip was studied. A study was conducted to understand the flow field and the winglet control techniques. Based on the study, a wing configuration was chosen as baseline configurations and different injection velocities were applied to this configuration. The chord wise pressure distribution is seen to change with the span wise location from the root and this distribution is affected by the wing tip vortex. The wingtip was observed to change the pressure distribution near the tip. The velocity field, stream lines and the vortices were seen to be affected by the presence of the injection. The lift and drag values were seen to decrease with the angle of attack but the l/d ratio remained nearly constant for all the injection configurations. Maximum reduction in drag of nearly 19% could be achieved with the injection. This study proved the possibility of using span wise injection as a control method to control the wing tip vortex.