This paper deals with comparative study of wind-induced mutual interference effects on twin Square and Fish- plan shape building models having equal volume. Wind induced pressure and force is measured through experiments under boundary layer wind tunnel for interference and isolated wind incidencecondition with building model of scale 1:300. For isolated condition’s study two wind incidences i.e. 0⁰ and 180⁰ is considered whereas; for interference conditions five different orientation of twin interfering building models are considered. The distance between the twin building models is fixed at 10% of the height of principal model. The variation of coefficient of wind pressure on different surfaces of the model is shown by contour plots. To examine the mean variation along the faces Face-Average C_p has been calculated, plotted and discussed to a great extent. The interference study is done in order to understand the effects of different conditions that can arise in real life situations and the differences associated with them. The concluding remarks states the dominance of Drag and Lift forces at isolated 0⁰ and 180⁰ wind incidences for Fish- plan shape model and at isolated 0⁰ wind direction at Square shape model. Also, the overall efficiency in terms of Base shear of principal building is enhanced due to interference effect; with maximum efficiency exhibited by Back-to-Back wind interferencen condition when only Fish- plan shape model is considered. Overall, maximum efficiency in terms of induced wind pressure and base shear is exhibited by Square- plan shape model at Full Blockage condition.

Tall buildings are mainly designed to resist wind loads because wind-induced vibration is more critical for occupant’s comfort level on top of the building. Therefore, evaluation of wind-generated pressure is must for such type of tall buildings. Investigation of response due to wind loads on tall buildings is possible by employing numerical modelling such as computational fluid dynamic tools. Regular plan shape structure can be designed for wind load using various international standards and available literatures. In this research comparisonis made between four models in which model-A and B is having the regular shape while model-C and D are of irregular shape. These study is useful for the designer to evaluate the response of structures under strong wind conditions. The grid sensitivity and validation study are performed for rectangular shape tall buildings. Validation of the study shows that numerical simulation results are more or less identical with experimental results. In present research work selected building models have equal cross-sectional area and height. Numericalstudy performed by employing the k-ε turbulence model and the results are compared with the experimental findings. Out of all the four models, the Y-shape model with round in corners has a minimum base moment and the least coefficient of drag.