The increasing utilization of diverse construction materials and innovative designs in the field of high-rise building construction underscores the necessity for precise insights into wind dynamics and pressure distribution across building facades. The knowledge is essential for achieving a harmonious balance between the functional and structural aspects of building design. While extensive research has been conducted on conventionally structured building models, serving as the foundation for the development of international wind design codes in various countries. Codal values remains a noticeable scarcity of research focused on buildings with irregular plan shapes. The research gap calls for a deeper understanding of the unique challenges posed by irregular building designs and underscores the importance of conducting comprehensive investigations in this domain. A general estimation of magnitude of wind pressure on faces of any bluff body is taken as mean pressure coefficient (). It is a dimensionless measure which largely depends upon the shape and size of the bluff body, and surrounding topographical characteristics. External mean pressure coefficient () is almost independent of the velocity of flow. The oblique wind also creates different wind flow pattern around the body, and results in varying velocity pressure on the surfaces.
Investigating wind effects through a combined approach of numerical simulations and real-world experiments is a critical endeavour in understanding and mitigating the impact of wind on various high-rise structures. This interdisciplinary approach enables researchers and engineers to gain comprehensive insights into the behaviour of wind, contributing to more effective design and safety measures. The wind effects on a high-rise building model may be explored using experimental (wind tunnel method) as well as using numerical simulation. Few researchers studied pressure pattern on a square shape building model [
1,
2,
3] The contour isobars of mean wind pressure on different faces of the model. It was demonstrated that upwind side of the model is exposed to positive pressure but on side faces, top and backward faces, negative pressure do exist. Subsequently, pressure distribution and wind load studies on varying size and height of regular tall buildings such as square, rectangular, circular etc. were carried out by different researchers. Guidelines for design of structures against wind loads have been made after analysing wide range of data from the studies and international standards [
4,
5,
6,
7,
8,
9] (field measurements and experimental studies) in the form of codes/standards. But due to scarcity of land in urban and metropolitan cities and evolution of new construction materials and technologies, height of the buildings has to be maximized along with usage of irregular shapes as building cross section, to fit in the available topography of land. Wind tunnel studies are conducted to investigate the wind generated effects on high rise structures, which is time consuming and cumbersome. Using the latest technology and development in the computational resources now a days numerical simulations are gaining importance. It provides faster and economical solution within the comfort of office. Full scale measurements can also be done in numerical simulations. Behavior of irregular shape buildings under wind load have been studied by many researchers on wind tunnel and/or numerically. For example, wind pressure pattern along the perimeter of L and U shape buildings in plan of similar height were studied on wind tunnel and numerically [
10] Similarly, along and across wind effects as well as interference effects on a model of tall rectangular building were studied by [
11] by using wind tunnel tests and Computational Fluid Dynamics (CFD). It is observed from the study is that the percentage difference between the results from wind tunnel test and CFD to be between 20 % to 25 %. Field measurement results of two super tall buildings were compared with wind tunnel data for two terrain characteristics – open country and urban terrain [
12]. The predicted design load
value for clad buildings is modified by wind directionality factor
and area averaging factor
[
4]. Various research works is in the field of wind engineering on irregular shapes of buildings. Aerodynamic forces and wind pressure on various unconventional plan shaped tall buildings were presented by [
13,
14]. The wind directionality and side ratio of a rectangular building modify suction pressure on side faces and lee face. Pressure envelope around the faces of a regular E plan shape building model for various wind directions was studied by [
15]. Fluctuating forces and pressure due to wind on a super tall building model for isolated and surrounded conditions for different wind directions were studied [
16]. The wind flow parameters around N cross-section of tall building [
17]. Surface pressure on faces of a C-shaped building model with different aspect ratio was investigated [
18] on ANSYS (Fluent) using
turbulent model for different wind incidence angles and the results were compared with wind tunnel results. Interference effect on a rectangular building due to another building placed to form an L-shape in plan were studied through modelling in STAAD Pro with varying height of the interfering building by [
19]. Effect of side ratios on wind imparted load on a Y shape tall building was studied [
2,
20,
21] using numerical simulations. A compression of results obtained from
and SST turbulence models and experimental data were made. The results from obtained from
turbulence model was similar to wind tunnel experimental results. Although, Plus-plan shape is a very common shape, experiments on such plan shape buildings have generally been conducted for normal wind directions only. [
22] investigated wind effects on a plus shape building model with varying re-entrant wing lengths and compared the results with a square model of similar plan area Both, the cross-sectional shapes and wind directions, were found to influence the base shear, base moments, and twisting moment acting on the model. [
23] reviewed the results from on a tall building with a plus shape for 0° and 45° wind angles experimentally and numerically, both. It was observed that the variations in pressure coefficients between the wind tunnel test and the numerical approach were within the acceptable range.
In the current research study, a unique and innovative investigation by focusing on the surface pressure distribution of a plus-shaped building model is made the building exhibits distinctive characteristics, with a cross-sectional area of 300 square meters and a height of 50 meters. The main focus of the study lies on the wind generated effects on re-entrant corner of tall building. The numerical simulation is performed using k-epsilon turbulence model, the wind velocity is applied as power low and for the building model the length scale ratio is selected based on the guideline available in various international standards.In this research the coefficient of pressure (Cpe), Stream lines in the vertical as well as on the specific surface of re-entrant corners, pressure contours and pressure distribution for various wind incidence angle is presented in different graphical forms.