Aerofoil Profile Research Articles

Impact of Aerofoil Shapes on the Performance of Darrieus Vertical Axis Turbines: A Computational Study for Offshore Wind and Hydro Applications

Abstract An increasing energy demand, coupled with the depletion of fossil fuels and rising pollution levels, necessitates a shift towards renewable energy sources. Wind and hydro energy are a prominent renewable energy source, constituting more than 20% of the global electricity production. The objective of this study is to investigate the influence of different aerofoil shapes on the performance of Darrieus vertical axis turbine for the optimum tip speed ratio of 3.0 using Computational Fluid Dynamics (CFD) simulations. The focus is on six aerofoil profiles, namely, NACA 0012, NACA 0021, NACA 0030, S-1046, NACA 4421 and NACA 2412. Open-source CFD software OpenFOAM 9.0 is employed to perform two-dimensional unsteady Reynolds-Averaged Navier-Stokes (U-RANS) simulations using the SST k-ω turbulence model. This approach allows for the analysis of fluid characteristics around the turbine blades and an assessment of the aerodynamic performance of Darrieus turbine. The observed results provide an insight into the performance of various aerofoil profiles and help understand their strengths and shortcomings. By comparing the results, the aerofoil shape that yields the highest performance under the given conditions is identified. Additionally, the study investigates the effect of using asymmetric aerofoils on Darrieus turbine performance. This study is relevant to the optimization of the aerofoil shapes which can further enhance the efficiency and effectiveness of Darrieus turbines.

Optimizing Aerofoil Design: A Comprehensive Analysis of Aerodynamic Efficiency through CFD Simulations and Wind Tunnel Experiments

This study explores the aerodynamic properties of different aerofoil shapes and their performance under varying flow conditions to identify the most efficient design based on lift-to-drag ratio, stall behaviour, and overall aerodynamic efficiency. Using Computational Fluid Dynamics (CFD) simulations, several aerofoil profiles were analysed at different angles of attack and flow speeds. These simulations were validated through wind tunnel experiments, offering a comprehensive understanding of aerofoil performance in real-world scenarios. The combination of CFD analysis and wind tunnel testing enabled a thorough assessment of each aerofoil shape, leading to the discovery of a specific aerofoil with a high lift-to-drag ratio and stable performance at high angles of attack. These results have significant implications for the design of wings and blades in aerospace and aeronautical applications, improving fuel efficiency and performance in both aviation and wind energy sectors. Additionally, dynamic roughness shows potential in reducing separation bubbles, but further investigation is needed to assess its effectiveness at higher angles of attack and elevated Reynolds numbers. Understanding the scalability and practical application of dynamic roughness in real-world scenarios is essential. Current research on surface modifications like dimples and riblets lacks optimized configurations for varying conditions. More research is needed to understand the interaction between surface geometries and the boundary layer, particularly at higher angles of attack and Reynolds numbers. Combining experimental and numerical methods can provide a comprehensive understanding of flow control techniques. The limited research on applying flow control strategies to wind turbine blades indicates a significant opportunity to improve wind energy efficiency. Future studies should focus on optimizing multiple techniques and addressing practical challenges, such as durability, cost-effectiveness, and integration into existing systems. Investigating the cost-effectiveness and durability of these modifications for long-term use will be vital for their successful adoption in the industry. Expanding research to include the effects of environmental factors like temperature and humidity will offer a more complete understanding of flow control in various operating conditions. By addressing these gaps, advancements in aerodynamic performance can be achieved, benefiting the aerospace and wind energy sectors.

Investigation of Lifting Force Affected by the Velocity and Angle of Attack (AoA) In Wing-in-Ground (WiG) Craft

The Wing-in-Ground (WIG) craft represents a pioneering vehicular innovation that exploits aerodynamic lift via a cushioning mechanism, enabling it to remain suspended above the water's surface. A notable concern encountered during the navigational manoeuvres of the WIG craft over the uneven sea terrain pertains to its potential impact on fuel efficiency during flight durations. This research objective is focused on the pivotal of ascertaining the optimal lifting force prerequisites for a prototype WIG craft. This comprehensive study entails an exploration of diverse combinations of velocities and angles of attack (AoA) to identify the most suitable configuration capable of attaining the requisite lift force levels. The study's methodology revolves around the adaptation of the actual WIG concept, encompassing a focus on the aerofoil profile and leveraging insights garnered from a design concept pertaining to WIG craft. To emulate real-world scenarios with precision, computational simulations employing the flow simulation capabilities of SolidWorks software are executed concurrently with the validation of a fabricated prototype. Parameters encompassing, angle of attack, and velocity are meticulously configured, adhering to the commonly employed parameters within the realm of WIG craft operations. The resulting outcomes are rigorously validated and subsequently compared against a lift coefficient of 1.25 at an angle of attack set at 16°, consistent with outcomes from prior research activities. This established angle of attack serves as a foundational reference for the present study's empirical conclusions. The culmination of these simulations yields the identification of an optimal arrangement characterized by a velocity of 120 km/h coupled with an angle of attack measuring 20°. This particular configuration consistently stimulates the requisite magnitude of lift force, thereby demonstrating the feasibility of elevating the WIG craft prototype without compromising stability or safety.

Numerical investigation on the effect of slit thickness and outlet angle of the bladeless fan for flow optimization using CFD techniques

The effect of outlet thickness and outlet angle of the bladeless fan have been an alysed numerically on the aerodynamic performance of the bladeless fan. Five different aerofoil profiles have been considered for the present work is Eppler 479, Eppler169, Eppler 473, S1046 and S1048. The bladeless fan arrangement has been achieved by converting the aerodynamic models listed above. The ANSYS ICEM CFD 16.0 have been used to discretize the enclosure and bladeless fan through finite volume approach. The mesh model is then imported into ANSYS CFX 16.0 pre-processor for applying the required boundary conditions. The governing equations namely continuity and momentum are used to solve the flow physics through and across the bladeless fan and SST k-? turbulence model has been used to predict the turbulence in the bladeless fan. The effect of outlet thicknesses and outlet angles have been varied for all the five aerofoil configurations mentioned and the volumetric flow at inlet have been adjusted from 5 LPS to 80 LPS. Outlet thickness is varied from 0.8, 1.0, 1.3, 1.5 and 2 mm and the slit angle is varied from 20 degrees to 80 degrees in step of 10 degrees. The results predicted that Eppler 473 aerofoil profile showed better performance when the thickness of slit and outlet angle has been fixed constant as 1 mm and 70 degree respectively. Also, the maximum discharge flow ratio is recorded for an inlet volumetric flow rate of 80 LPS and it is found to be 34.37. The present numerical study substantiated that outlet thickness plays a dominant role on the bladeless fan’s aerodynamic performance compared to outlet angle and aerodynamic shape considered in this numerical analysis. The contours of velocity, streamline and pressure of the bladeless fan have been discussed.

Numerical investigation on the effect of slit thickness and outlet angle of the bladeless fan for flow optimization using CFD techniques

The effect of outlet thickness and outlet angle of the bladeless fan have been an alysed numerically on the aerodynamic performance of the bladeless fan. Five different aerofoil profiles have been considered for the present work is Eppler 479, Eppler169, Eppler 473, S1046 and S1048. The bladeless fan arrangement has been achieved by converting the aerodynamic models listed above. The ANSYS ICEM CFD 16.0 have been used to discretize the enclosure and bladeless fan through finite volume approach. The mesh model is then imported into ANSYS CFX 16.0 pre-processor for applying the required boundary conditions. The governing equations namely continuity and momentum are used to solve the flow physics through and across the bladeless fan and SST k-? turbulence model has been used to predict the turbulence in the bladeless fan. The effect of outlet thicknesses and outlet angles have been varied for all the five aerofoil configurations mentioned and the volumetric flow at inlet have been adjusted from 5 LPS to 80 LPS. Outlet thickness is varied from 0.8, 1.0, 1.3, 1.5 and 2 mm and the slit angle is varied from 20 degrees to 80 degrees in step of 10 degrees. The results predicted that Eppler 473 aerofoil profile showed better performance when the thickness of slit and outlet angle has been fixed constant as 1 mm and 70 degree respectively. Also, the maximum discharge flow ratio is recorded for an inlet volumetric flow rate of 80 LPS and it is found to be 34.37. The present numerical study substantiated that outlet thickness plays a dominant role on the bladeless fan’s aerodynamic performance compared to outlet angle and aerodynamic shape considered in this numerical analysis. The contours of velocity, streamline and pressure of the bladeless fan have been discussed.

Fabrication of UiTM’s Energy Glider

Glider is a fixed-wing aircraft which does not depend on the engine. A glider can fly for an extended period depending on the design and area of the lifting surface. Just like any other aircrafts, the design of wings is crucial to produce lift force to keep aircraft in the air. Gliders have long wings and is designed to be lightweight which allows it to have a high lift-to-drag ratio (L/D) to glide at a long distance. The maximum lift-to-drag ratio, 〖(L/D〗_max) can indicate how far the glider will glide as it is one of the most important performance parameters. This project aims to design, build, and fly an energy glider. Prior on the design of the energy glider, statistical analysis has been done by comparing data from many studies to aid in determining the initial values of the glider. Then, the general design of the energy glider has been decided during the preliminary design. To support the design decision made, ANSYS Fluent software has been used to study flow of air over KFm-5A aerofoil profile which has been chosen during the early stages of design. The model of the energy glider was then designed in CATIA V5 software with a wingspan of 1.52 m and fuselage length of 0.69 m. Lastly, flight test was conducted to achieve the project’s objective. During the flight test, the glider reached a ceiling height of approximately 300 m and obtained a velocity of 144 km/h. The analysis of the glider performance will be used as an aircraft data for future research.

Low- and High-Fidelity Aerodynamic Simulations of Box Wing Kites for Airborne Wind Energy Applications

High aerodynamic efficiency is a key design driver for airborne wind energy systems as it strongly affects the achievable energy output. Conventional fixed-wing systems generally use aerofoils with a high thickness-to-chord ratio to achieve high efficiency and wing loading. The box wing concept suits thinner aerofoils as the load distribution can be changed with a lower wing span and structural reinforcements between the upper and lower wings. This paper presents an open-source toolchain for reliable aerodynamic simulations of parameterized box wing configurations, automating the design, meshing, and simulation setup processes. The aerodynamic tools include the steady 3D panel method solver APAME and the CFD-solver OpenFOAM, which use a steady Reynolds-Averaged Navier–Stokes approach with k-ω SST turbulence model. The finite-volume mesh for the CFD-solver is generated automatically with Pointwise using eight physical design parameters, five aerofoil profiles and mesh refinement specifications. The panel method provided accurate and fast results in the linear lift region. For higher angles of attack, CFD simulations with high- to medium-quality meshes were required to obtain good agreement with measured lift and drag coefficients. The CFD simulations showed that the upper wing stall lagged behind the lower wing, increasing the stall angle of attack compared to conventional fixed-wing kites. In addition, the wing tip boundary layer separation was delayed compared to the wing root for the straight rectangular box wing. Choosing the design point and operational envelope wisely can enhance the aerodynamic performance of airborne wind energy kites, which are generally operated at a large angle of attack to maximise the wing loading and tether force, and through that, the power output of the system.

Structural and thermal analysis on high-pressure steam turbine blade to determine the optimum material for its manufacturing

Blades of turbines are key elements of steam turbines. They are the main energy driven components at every stage of steam turbine where steam is pressurized to generate power. In view of designing, the material used and dimensions of blade govern the efficiency, consistency and durability of a steam turbine. In this paper the design of aerofoil profile of HP steam turbine blade is modelled by using computer-aided three-dimensional interactive application (CATIA). Various analytical data viz.., static structural analysis, transient structural analysis and transient thermal analysis are performed on different materials (ATI 720, Waspaloy, Molybdenum TZM, Incoloy alloy, Inconel alloy 725). Based on the analysis, Waspaloy material blade outperformed among all blades materials in terms of creep resistance and heat flux.

Minimisation of Shape Deviation Between an Inflatable Aerofoil and a Target Areofoil Profile

The use of inflatable wings for unmanned aerial vehicles over their fixed-winged counterparts has many advantages. However, there are difficulties associated with predicting the profile of the inflatable wing, which makes achieving a desirable aerofoil profile non-trivial. This research aimed to formulate a design methodology which would determine the uninflated geometry for an inflatable aerofoil profile, accurately fitting that of a target or prescribed profile. The aspects omitted from the scope of this work includes the aerodynamic performance and stiffness of the inflated aerofoils. The resulting uninflated geometry is suitable to construct a physical model. The methodology proposed incorporates numerical shape optimisation on finite element models. A series of structured numerical experiments determine robusticity of the established methodology by altering the thickness of the target aerofoil profile and increasing its complexity. For each case, the methodology successfully satisfied its aim, producing accurate fits between the inflated numerical model and the target aerofoil profile. When validated, the inflated shape of the numerical model proved to predict that of its corresponding physical model accurately for both simple and more complex geometries.

Numerical Investigation on the Effect of Geometric Shape and Outlet Angle of a Bladeless Fan for Flow Optimization using CFD Techniques

A three dimensional numerical study has been carried out to investigate the effect of various geometric shapes and slit angle on performance of the bladeless fan for various aerodynamic profiles. Aerofoils considered for the present study are E169, E473 and E479 which are then reformed into a typical bladeless fan arrangement. The numerical model of bladeless fan encompassing the outer domain is discretized tetrahedrally through finite volume approach using ANSYS ICEMCFD 20.0 and the necessary boundary conditions are specified in the ANSYS Fluent 20.0 pre-processor. The three dimensional fluid flow variations through and across the aerofoil have been simulated by solving the appropriate governing equations namely continuity and Reynolds Averaged Navier-Stokes equations (RANS). The turbulence induced in the fluid is modelled using SST k-ωmode of closure. Numerically predicted results of lift, drag and streamwise velocity decay along the jet centreline of a cylindrical channel are compared with literature and a very close agreement exists between the two. Upon validation, geometric shapes - circular and square cross section with aspect ratios of 1, 1,5 and 2 and slit angles of 20, 40, 60 and 80 degree for all the above three aerofoil configurations are analysed numerically for various inlet Reynolds number. Pressure, velocity contours and stream line across the bladeless fan are presented and discussed. From the study it is observed that Eppler 473 aerofoil profile with slit thickness of 1 mm and slit angle of 80° provided the maximum discharge ratio of 34.17 for an inlet mass flow rate of 80 LPS.

Development of mullite-alumina ceramic shells for precision investment casting of single-crystal high-pressure turbine blades

Alumina-mullite ceramic shell moulds were developed to cast single-crystal hollow high-pressure turbine blades (SX-HPTB). Mullite and fine alumina powders were used as fillers. Two colloidal silica binders were used to bind the filler particles. One colloidal silica binder (binder A) had no polymer and the second colloidal silica binder (binder B) had 8 wt % polymer. Eight slurry compositions with fine alumina substitution (0, 10, 30 and 50 wt %) were prepared. Silica cores were used to achieve hollow castings. The effect of alumina substitution and binders on the slurry characteristics, flexural strength of green and fired samples, air permeability and self-load sag resistance was studied. It was observed that with an increase in alumina percentage, the test specimens showed increased viscosity, pick-up weight, density, green strength and fired residual strength. In addition, the slurries prepared from binder B possessed larger values of viscosity and pick-up weight compared to the slurries prepared from binder A. The residual strength of fired test specimens containing binder A was higher than those containing binder B. The test specimens with 30 wt % fine alumina substitution showed the highest self-load sag resistance w.r.t. each test temperature. Also, the air permeability of the fired samples was higher than the green (de-waxed) samples. The casting of hollow HPTB components was performed at two temperatures (1525 °C and 1550 °C) using nickel-based superalloy CMSX4. The HPTB components, cast at 1550 oC from ceramic shell mould having binder B and 30 wt % fine alumina substitution, resulted in an acceptable aerofoil profile and surface roughness.

Performance Analysis of H-Darrieus Wind Turbine with NACA0018 and S1046 Aerofoils: Impact of Blade Angle and TSR

Despite the widespread research and development of HAWTs in recent times, VAWTs are gaining in popularity due to certain critical advantages they provide, for example, wind direction independency. While most existing studies focused on analysing the performance of VAWT using NACA aerofoils, this study compares the performance of NACA0018 and S1046 aerofoil profiles for a range of Speed Ratios (TSRs) and blade pitch angles. It has been found that the S1046 is less sensitive to changes in wind speed, and is thus, a superior choice for urban applications where the wind speed is comparatively low and varies a lot. Three bladed VAWTs of solidity 0.1 was modelled using Solidworks for this study. The CFD simulations were then performed in ANSYS Fluent, utilising the k-ω SST turbulence model. The model was validated at first before analysing the VAWT performance with the intended aerofoils. Key results indicate that increasing the TSR leads to increases in aerodynamic performances for nearly all cases, and especially so, for lower blade pitch angles. However, this study concludes that VAWT consisting of S1046 aerofoils at -2 degrees of blade pitch and operating at TSR 4 will provide the optimum performance.

Analysis of NACA 0020 aerofoil profile rotor blade using CFD approach

Impact of aerofoil blade design and their selection is one of the significant parameter in power generation using Savonius Vertical Axis Wind Turbine. Vertical Axis Wind Turbine (VAWT) is designed to fulfil human needs. In terms of total cost from an environmental standpoint, it is moderately very cheap when compared to current conventional methods. Kinetic energy, or wind velocity, is used to generate electricity by modifying mechanical energy, which is abundant and limitless. There would be no pessimistic impacts on the environment if such classifications were used. This method is superior to other conventional ways because the upkeep and operating costs are minimal. The principle reason behind the study is to evaluate the performance of a Savonius types Vertical Axis Wind Turbine (VAWT) on a NACA 0020 aero foil profile blade at various wind speeds, solidity ratio using CFD Analysis. The blade is designed to have a 00 angle of attack and a curvature of 150 on blade profile. Output power is calculated at variable speeds based on the speed of the rotor and the power available in the wind.

The influence of the flow separation bubble and transition location on the profile drag of three 4-digit NACA aerofoil profiles

Modeling of the flow over aerofoil profiles at low Reynolds numbers is difficult due to the complex physics associated with the laminar flow separation mechanism. Two major problems arise in the estimation of profile drag: (1) the drag force at low Reynolds numbers is extremely small to be measured in a wind tunnel by force balance techniques, (2) the profile drag is usually calculated by pressure integration, hence the skin friction component of drag is excluded. In the present work, three different 4-digit NACA aerofoils are investigated. Measurements are conducted in an open-ended subsonic wind tunnel, while numerical work is performed by time Reynolds-averaged Navier Stokes (RANS) coupled with the laminar-kinetic-energy ( K-kl-w) turbulence model. The influence of the flow separation bubbles and transition locations on the profile drag is discussed and addressed. This paper gives important insights into importance of measurements at low Reynolds numbers for better aerodynamic loads predictions.

Development of a new aerofoil profile with a high lift-to-drag ratio for wind turbines using a low fidelity accurate optimization flow solver

Abstract A significant amount of work is performed on various aerofoil profiles to improve their characteristics for wind turbine applications. The main purpose is to increase the power output of wind turbines by increasing the lift-to-drag ratio of the aerofoil blade sections. However, most of the developed aerofoil profiles work well only at their design angles of attack and for low Reynolds numbers with a very dramatic stall that could significantly influence the characteristics of the aerofoil profiles and the performance of wind turbines. The present paper is conducted to develop a new aerofoil profile with more gradual stall characteristics that works efficiently for different operational conditions (clean and rough working conditions) similar to those encountered by wind turbines in the free environment. The new aerofoil profile was developed based on a combination between experimental Box–Behnken design and XFOIL code, measurements, and 2D simulation conducted by computational fluid dynamics (CFD) method. The established aerofoil can be used for wind turbine blades because it gives high lift-to-drag-ratios with very smooth and gradual stall characteristics even under very rough operating conditions.

Hydrodynamic analysis of an underwater glider wing using ANSYS fluent as an investigation tool

The analysis of the hydrodynamic behavior of the modified trailing edge of an underwater glider wing was conducted using ANSYS Fluent 18.1. The procedure was carried out using the computational fluid dynamics (CFD) approach. A standard four digits NACA0016 aerofoil profile was selected while the geometry points were extracted from NACA online aerofoil generator using Solidworks, which enabled the creation of the 3D wing profile. Since the focus of the study is more toward hydrodynamic behavior or the influence of the modified round trailing edge as opposed to the normal sharp trailing edge, coefficient of lift (CL), coefficient of drag (Cd), coefficient of pressure (Cp) and the drag polar (Cd/CL) are very crucial parameters and have an influence on the accuracy of the results. The results showed lift and drag coefficient are a function of the angle of attack (AOA) and free stream velocities. The investigation showed the optimal design point of the AOA of 12° at the corresponding speed of 0.26 m/s. The critical AOA matched with the optimal design point of 12°. The results also showed that Cp is higher closer to the fuselage and therefore explains why more structural rigidity must be provided in this region of high stress concentration. The drag and lift curve corresponded to the typical wing characteristics of the published experiment data regardless of the operating conditions.

Fluid Structure Interaction Analysis of Horizontal Axis Wind Turbine

Wind power is a clean energy source that we can rely on for long term use. A wind turbine creates reliable, cost effective pollution free energy. A Horizontal axis wind turbine (HAWT) with three blades having aerofoil profile NACA 2421 is modelled in CAD software and the performance of the turbine is investigated numerically using 3D CFD Ansys 18.1 software at rotor speeds varying from 1 to 7.5 Rad/sec at wind speeds ranging from 8 to 24 m/s. In order to ensure the turbine blades do not fail due to pressure loads and rotational forces, Fluid structure interaction is carried out by importing the surface pressure loads from CFD output on to static structural module, the rotational velocities are also imparted on the blades and FE analysis is carried out to estimate the equivalent von-Mises stress for structural steel as well as aluminium alloy. It is found that aluminium alloy blades are preferable than the structural steel blades. At high rotor speeds, stresses in the structural steel exceeding the yield strength limit. For aluminium alloy the stresses are below the yield strength limit.

Enhancement of Heat Transfer Characteristics using Aerofoil Fin over Square and Circular Fins

The thermal conductivity of fin material, its geometrical profile and the mode of heat transfer etc, are the key factors which generally affects the heat transfer from fins. The present research deals with the improvement in heat transfer characteristics and the investigation of fin performance efficiency by using fins of varying geometrical profiles in pin fin apparatus. In this study the heat transfer characteristics inside a rectangular duct with circular, square and aerofoil geometrical profiles of fins were analyzed experimentally. The intention of the present work is to evaluate the heat transfer coefficient, Reynolds number, Nusselt number, pressure drop and efficiency of fin with circular, square and aerofoil geometrical profiles and all the results obtained will be compared with those from a circular fin of same material surface. In the present study, experimental results of the heat transfer characteristics of all the three geometrical profiles of fins under constant heat flux conditions are presented. Experiments are performed at various Reynolds numbers in the range of 1000–9000 and heat fluxes in the range of 0.91–3.64 kW/m2. The predicted results are validated by comparing with measured data. The predicted results are in reasonable agreement with the experiments. It is found that with increase in Reynolds number, the Nusselt number and thermal performance increases, for a fin having aerofoil profile as compared with a fin with square and circular profile. These are because of delayed separation of air and increase in contact time for a fin having aerofoil profile as compared with a fin with square and circular profile.

Leading-edge tubercles delay flow separation for a tapered swept-back wing at very low Reynolds number

Flow separation characteristics for two tapered swept-back wings, one with straight leading-edge (LE) and the other with tubercled LE, were investigated in a water tunnel using time-resolved particle image velocimetry (TR-PIV) technique. The two wings were based on the SD7032 aerofoil profile, with Reynolds number Re = 1.4 × 104, close to the working condition for common underwater gliders. The LE tubercles were designed such that the amplitude decreased linearly from the wing root to wing tip, while retaining constant wavelength. Results indicate that the baseline wing shows significantly separated flow in the outboard region at pitch angle of 10° and 20°, and the flow remains attached in the inboard region due to relatively larger local Reynolds number. Implementation of LE tubercles can mitigate flow separation downstream of both troughs and peaks. At higher pitch angles, the separated flows cover most of the baseline wing surface, whereas flow remains attached downstream most of tubercle peaks. Streamwise aligned counter-rotating vortex pairs (CVPs) formed over the tubercles are significantly tilted and asymmetrical due to the sweep and amplitude difference between the two sides of tubercle. Consequently, weaker vortices in CVPs close to the wing root are rapidly dissipated, allowing the CVPs to evolve into a series of co-rotating vortices (CVs), which exerted significant impact on flow separation characteristics downstream of the tubercles.

Performance of buoyant shell horizontal axis wind turbine under fluctuating yaw angles

The paper presents the effect of fluctuating yaw angle and wind speed on the performance of a horizontal axis airborne wind turbine of three different shell shapes for the high altitude operational conditions. For this purpose, a numerical analysis has been performed by considering the ranges of yaw angle and wind speed of 0°−20° and 10m/s−25m/s, respectively. The turbine shell shapes are based on the three aerofoil profiles of NACA-5415, NACA-9415 and NACA-5425 to investigates the influence of the aerofoil camber and thickness. The turbine has been modelled using a NREL Phase IV rotor with the fixed rotor radius of 2m for all shell configurations. A 3-D numerical analysis has been conducted by implementing k−ω SST turbulence model to solve the Reynolds-averaged Navier-Stokes equations. Numerical results demonstrated that the increment in both the tip speed ratio and yaw angle augmented the rotor thrust coefficient. At the high yaw angles, the buoyant shell is prone to encounter instability due to unbalancing of the aerodynamic forces subjected to the shell body. Among all the studied shell configurations, the NACA-9415 aerofoil based shell displayed the relatively higher turbine power coefficient as well as the stable operation.