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This study investigates the aerodynamics of the airflow over low-rise houses subjected to turbulent cyclonic winds along the South-eastern peninsular India, routinely afflicted by tropical cyclones. The purpose of this paper is to demonstrate how the power of modern computational fluid dynamics (CFD) and its engineering application accentuate decision-making at the planning stage of house designing in vulnerable areas.

The Weather Research and Forecasting (WRF) model was used for first simulating the landfall of cyclone Hudhud, a real storm, and its effect in extant and new house designs. Results from the WRF model were utilized to configure further CFD simulations of airflow around house designs. The analyses yielded deep insights, often non-intuitive, into airflow patterns around these houses with disparate roof forms indicating new possibilities in redesigning houses along Indian coastal areas.

This study shows that storm-induced high TKE values warranted a fuller CFD-based study. The second major finding showed that for a 90° angle of attack, arguably the most destructive attack angle, a pitched roof (with a pitch angle of 10°) worked best – this is about half the recommended angle sourced from earlier empirical estimates dating back to the British Raj period. There is a thin layer of padded air cushion shielding the roof's vulnerable surface from the storm's most energetic parts.

The originality of this research lies in its discourse to systematically resolve the TKE distribution of a cyclone impacting a standalone house. In particular, the study presents a lucid demonstration of all the probable scenarios connecting cyclonic stresses with a roof response, inferred from a careful combination of results garnered from cyclonic storm modelling coupled with CFD analysis. Additionally, the paper also shows a graphic visual representation of the forces induced on different roof designs, presented as a checklist for the first time. This should serve as a ready reckoner for civic authorities involved in disaster management over cyclone-ravaged areas.

Natural ventilation is an environmentally friendly effective way of improving thermal comfort and the quality of indoor conditions if applied properly. This study aims to investigate the physical mechanism of the air movement and also the influence of building geometry in a cross-ventilated room through a parametric study of window geometrical characteristics using computational fluid dynamics.

Momentum and continuity equations are solved by the control volume method using a commercially available software. Standard k−ɛ turbulence model is employed to simulate the incompressible airflow and SIMPLE algorithm to solve the conservation equations. Mean air velocity magnitude is measured at three different surfaces of different heights, and the effect of incoming wind velocity inside the building is studied.

The research concluded that window hood and sill projections reduce indoor wind velocity magnitude, play a major role in incoming wind direction and thus have a crucial impact on wind circulation and indoor air quality.

The paper has evaluated redesigning of a both practical and ornamental architectural element named Palekaneh, which is found in many historical buildings in several hot places in the world. Its optimal design could increase indoor natural ventilation quality and decrease a space's cooling load. Therefore, a new passive cooling architectural element could be re-introduced to the regions previously enjoying such ornaments. This is economically efficient because it eventually saves a considerable amount of energy in the long run and is socially important because of the revitalization of architectural identity.

The role of a building envelope's physical features, although being studied for solar absorption and daylight availability, has rarely been investigated for natural ventilation, especially in a small scale, thus making the paper novel in this regard. This provides a guideline for designers to assess the impact of their design on redirecting wind-induced natural ventilation the very early stages of design.

THE main objectives of French aeronautical progress have been safety in flight, development of commercial aviation, and metal construction. In every part of aeronautical science we shall find progress along those lines. They concern aerodynamics, building of aircraft, flying boats, motors and aerial navigation.

In recent years, fire accidents in engineering structures have often been reported worldwide, leading to a severe risk to life and property safety. The present study is carried out to evaluate the performance of Ground Granulated Blast Furnace Slag (GGBS) and fly ash–blended laterized mortars at elevated temperatures.

This test program includes the replacement of natural river sand with lateritic fine aggregates (lateritic FA) in terms of 0, 50 and 100%. Also, the ordinary Portland cement (OPC) was replaced with fly ash and GGBS in terms of 10, 20, 30% and 20, 40 and 60%, respectively, for producing blended mortars.

This paper presents results related to the determination of residual compressive strengths of lateritic fine aggregates-based cement mortars with part replacement of cement by fly ash and GGBS exposed to elevated temperatures. The effect of elevated temperatures on the physical and mechanical properties was evaluated with the help of microstructure studies and the quantification of hydration products.

A sustainable cement mortar was produced by replacing natural river sand with lateritic fine aggregates. The thermal strength deterioration features were assessed by exposing the control specimens and lateritic fine aggregates-based cement mortars to elevated temperatures. Changes in the mechanical properties were evaluated through a quantitative microstructure study using scanning electron microscopy (SEM) images. The phase change of hydration products after exposure to elevated temperatures was qualitatively analyzed by greyscale thresholding of SEM images using Image J software.

To the student of air transport this must be one of the most fascinating volumes to appear in recent years, and Mr Stroud must be congratulated on the result of his efforts to portray in a single work the technical details and history of all transport aircraft designed and built in Europe which have been used in airline service. For good measure, he includes particulars of some aircraft that never went into service but have a place in the history of airline development.

For flow around elongated bluff bodies, flow separations would occur over both leading and trailing edges. Interactions between these two separations can be established through acoustic perturbation. In this paper, the flow and the acoustic fields of a D-shaped bluff body (length-to-height ratio L/H = 3.64) are investigated at height-based Reynolds number Re = 23,000 by experimental and numerical methods. The purpose of this paper is to study the acoustic feedback in the interaction of these two separated flows.

The flow field is measured by particle image velocimetry, hotwire velocimetry and surface oil flow visualization. The acoustic field is modeled in two dimensions by direct aeroacoustic simulation, which solves the compressible Navier–Stokes equations. The simulation is validated against the experimental results.

Separations occur at both the leading and the trailing edges. The leading-edge separation point and the reattaching flow oscillate in accordance with the trailing-edge vortex shedding. Significant pressure waves are generated at the trailing edge by the vortex shedding rather than the leading-edge vortices. Pressure-based cross-correlation analysis is conducted to clarify the effect of the pressure waves on the leading-edge flow structures.

The understanding of interactions of separated flows over elongated bluff bodies helps to predict aerodynamic drag, structural vibration and noise in engineering applications, such as the aerodynamics of buildings, bridges and road vehicles.

This paper clarifies the influence of acoustic perturbations in the interaction of separated flows over a D-shaped bluff body. The contribution of the leading- and the trailing-edge vortex in generating acoustic perturbations is investigated as well.

There is considerable evidence that long periods of success in organisations can lead to ossification of strategy and strategic inertia. Burgelman (2002) shows how co-evolutionary lock-in occurs through the creation of a strategy vector. He demonstrates that the internal selection environment can become configured to create sources of inertia that dampen the autonomous strategy process, driving out unrelated exploration and creating a dominance of the induced, top-down strategy process. While this study shows how lock-in occurs, it does not address how a company breaks out of co-evolutionary lock-in. This is the focus of this paper. We argue that to understand how an organisation breaks out of a strategy vector a more complete conceptualisation of the structural context, and in particular the under specified cultural mechanisms, is required. It also requires an understanding of the linkages between the structural context and the new core capabilities required for breakout. Thus we first expand on what is known about strategy vectors and review research from the strategy process tradition that explores the linkages between strategy, culture and strategic change, to build a more comprehensive picture of the structural context. Our model demonstrates the extent of interconnectedness between the ‘hard’ (e.g., control systems and organisation structure) and ‘soft’ (e.g. beliefs, symbols and stories) components, and that development of new required capabilities is dependent on a holistic shift in all these aspects of the structural context, including, therefore, change in the organisation's culture. We then illustrate the link between lock-in, capability development and culture change through the case of the famous Formula One team, Ferrari. We finish with a discussion of the implications of our findings for strategic change.

The purpose of this paper is the development of a new density-based (DB) semi-Lagrangian method to speed up the conventional pressure-based (PB) semi-Lagrangian methods.

The semi-Lagrangian-based solvers are typically PB, i.e. semi-Lagrangian pressure-based (SLPB) solvers, where a Poisson equation is solved for obtaining the pressure field and ensuring a divergence-free flow field. As an elliptic-type equation, the Poisson equation often relies on an iterative solution, so it can create a challenge of parallel computing and a bottleneck of computing speed. This study proposes a new DB semi-Lagrangian method, i.e. the semi-Lagrangian artificial compressibility (SLAC), which replaces the Poisson equation by a hyperbolic continuity equation with an added artificial compressibility (AC) term, so a time-marching solution is possible. Without the Poisson equation, the proposed SLAC solver is faster, particularly for the cases with more computational cells, and better suited for parallel computing.

The study compares the accuracy and the computing speeds of both SLPB and SLAC solvers for the lid-driven cavity flow and the step-flow problems. It shows that the proposed SLAC solver is able to achieve the same results as the SLPB, whereas with a 3.03 times speed up before using the OpenMP parallelization and a 3.35 times speed up for the large grid number case (512 × 512) after the parallelization. The speed up can be improved further for larger cases because of increasing the condition number of the coefficient matrixes of the Poisson equation.

This paper proposes a method of avoiding solving the Poisson equation, a typical computing bottleneck for semi-Lagrangian-based fluid solvers by converting the conventional PB solver (SLPB) to the DB solver (SLAC) through the addition of the AC term. The method simplifies and facilitates the parallelization process of semi-Lagrangian-based fluid solvers for modern HPC infrastructures, such as OpenMP and GPU computing.

THE advent of the metal‐ and ply‐covered plane has caused a number of one‐time academic problems in the theory of torsion to become of practical interest to the aircraft designer. Any satisfactory solution, therefore, of the academic problem implied in the title to this paper will be a step towards the more complete analysis of the stresses in the root portion of the metal‐covered wing.