Pre-stall Region Research Articles

Preliminary Numerical Modelling of a Dynamic Spring-Mounted Wing System to Reduce the Drag of Vehicles at Higher Speeds

The dynamic behaviour of a spring-mounted symmetrical NACA0012 wing in a freestream flow of air is studied in the pre-stall region, over 0° to 12° angles of incidence. The primary aim of this work is for use within the automotive sector to reduce drag and fuel emissions. However, this work will also be of interest in the motorsport sector to improve performance, and also have some applications within the aerospace and renewable energy sectors. The general operation of the concept has previously been verified at these low angles in the pre-stall region with that of a theoretical estimation using finite and infinite wings. This paper provides a numerical solution of the same problem and is compared with the previous experimentation. At these low angles, the computations yield a dynamic response settling into a static equilibrium. The stable solutions match the start of a steady regime well, when compared with the experiment. The trends are also comparable with the experiment, but the velocities at which they occur are underestimated in the computation. The computations demonstrate a drag reduction of 59% when compared to a fixed wing, whereas the lift remains stable at a near constant value with increasing wind speed. Thence, downforce is maintained whilst drag is reduced, which will facilitate higher speeds on the straight whilst maintaining vehicle direction stability. Limitations to this proof-of-concept work are highlighted and future development work is suggested to achieve even further increases in performance.

Investigation of dynamic characteristics of hydrofoil with leading-edge tubercles

The convex structure of a humpback whale flipper is included in the airfoil design to investigate the control principle of the dynamic stall process. The effect of two different types of tubercles on the dynamic stall process of airfoils was investigated. The distribution of dynamic hysteresis loops and pressure fields with streamlines was used to explain the properties of the dynamic flow field and the emergence of dynamic stall vortices. The results demonstrate that the airfoils with tubercles have stronger hysteretic characteristics in the pre-stall region, and the ζ CM of mod-1 is increased by 51.33%, indicating stronger torsional hydroelastic stability. In the post-stall region, mod-2 is always in a condition of significant flow separation, which impairs the torsional hydrodynamic stability of the airfoil and has the potential to cause flutter. These findings suggest that leading-edge tubercles offer a negligible advantage in reducing airfoil dynamic stall, and their significance warrants further investigation.

Effect of aero-shaped vortex generators on NACA 4415 airfoil

A parametric study was carried out to investigate the effect of aero-shaped vortex generators (AsVGs) on NACA 4415 airfoil by comparing conventional vortex generators (CVGs). Force and flow visualization experiments were carried out for the CVGs and AsVGs at Re = 1.4 × 105. Six different configurations were selected for the positioning of the CVGs to investigate the best one. The best configuration was applied to the Aero-shaped VGs type, which is generated with the S1223 airfoil model. The results indicated that even if AsVGs did not show better performance to delay the stall angle when compared with the CVGs, in some positions they produced the same stall performance as the CVGs. Moreover, aero-shaped VGs increased the lift coefficient (CL) more than the conventional ones in the pre-stall region. At x/c = 0.1, CL and CD improve by up to 107.7% and 23.39% compared to baseline, respectively. At α = 18° and Re = 0.8 × 105, AeM5 at x/c = 0.1 increased the CL by 102.45% compared to the baseline model. While the CVGs increased the lift coefficient (CL) and postponed the stall (α) angle up to 4° according to the baseline model, the CVGs also caused an overall increase in the drag coefficient (CD). AsVGs decreased the drag coefficient (CD) more than conventional ones. Lift to drag ratio (L/D) of AsVGs is higher than that of the CVGs. The results of the surface oil flow visualization showed that both CVGs and AsVGs segmented the laminar separation bubble (LSB) and formed attached flow zones on the airfoil surface. As a result, AsVGs can be used as an alternative to CVGs in flow control applications.

Effect of streamwise vane treatments on the noise reduction performance of trailing edge serrations under aerodynamic loading conditions.

Trailing edge serrations have shown remarkable ability to reduce noise, but their effectiveness can be significantly impacted by flow misalignment, particularly under aerodynamic loading conditions. This paper presents a comprehensive study on the effect of incorporating streamwise vane treatments at the root of the trailing edge serrations on its noise reduction performance. Experiments were performed on a 100 mm chord NACA 0012 wing model with sawtooth type trailing edge serration. The aeroacoustic performance was investigated for serrations with non-zero flap angle at various angles of attack between -5° and 8.5°. The findings reveal that streamwise vanes can reduce the high-frequency noise by over 5 dB when placed at the root. Furthermore, particle image velocimetry measurements in the wall-normal plane demonstrate a significant decrease in cross-flow and turbulence generation when the treatment was placed near the root of serrations. In addition, the load measurements indicate no noticeable variation in the lift coefficient and up to 6% increase in the drag coefficients in the pre-stall region.

Investigation of aerodynamic performance of Clark-Y airfoil with more realistic tubercle model and internal slots

An experimental study is conducted to research the combined effect of leading-edge (LE) tubercles and internal slots on the Clark-Y airfoil at Reynolds numbers (Re) of 5.0×104, 7.5×104, and 1.0×105 for angles of attack ranging from 0° to 30°. The Clark-Y is a cambered airfoil that performs well at low and medium Reynolds numbers, having a maximum thickness of 11.7% at 28% of the chord. Five different test models are the subjects of experiments, one of which is the baseline. The other test models are the Wavy model, which has LE tubercles, and the Wavy with three different slot positions: the Wavy-LES (leading-edge slot), the Wavy-MS (middle slot), and the Wavy-TES (trailing-edge slot). The LE tubercle geometry is formed by the sum of two sinusoidal wave functions with a realistic approach. In the present work, experimental studies are performed through force measurements, and detailed information on a 3-dimensional flow field is obtained by a surface-oil flow visualization technique. Force measurements indicate that the Wavy model delays stall and exhibits smoother stall behavior compared to the baseline. Moreover, the findings show that the lift coefficient (CL) of the Wavy model deteriorates in the pre-stall region with the inclusion of the internal slots but improves significantly in the post-stall region. Maximum improvement in CL in the post-stall region was achieved by 60% in Wavy-LES at Re of 5.0×104 as compared to the baseline. At Re of 5.0×104, Wavy and Wavy-MS present a better lift-to-drag ratio (CL/CD) than the other models in the pre-stall region, whereas the baseline is the best at Re of 1.0×105. The best CL/CD is achieved by Wavy-LES in the post-stall region, regardless of the Reynolds numbers. The variation of flow characteristics relevant to aerodynamic performance is revealed by surface oil flow visualization for all tested models.

Prediction of the near wall flow behaviours of separation and transition for NREL phase VI wind turbine blade

ABSTRACT This study demonstrates the separation and transition flow behaviour around a 3-D wind turbine blade by analysing blending functions, intermittency, and transition onset Reynolds number in SST Gamma Theta model. The National Renewable Energy Laboratory Phase VI rotor was modelled for the analysis. The simulations were executed by using the ANSYS-CFX solver. Extensive comparisons were performed to demonstrate the accuracy of this numerical model for sectional pressure distribution, tangent force, normal force, thrust, and torque. Good agreement was observed in all wind speed cases. The discrepancies in pre-stall region were negligible, and those in the post-stall region were acceptable. Thus, the capability and accuracy of the SST Gamma Theta model in predicting separated and transitional flow effects were verified.

Aerodynamic Optimization of Trailing-Edge-Serrations for a Wind Turbine Blade Using Taguchi Modified Additive Model

For the rotor, achieving relatively high aerodynamic performance in specific wind conditions is a long-term goal. Inspired by the remarkable flight characteristics of owls, an optimal trailing edge serration design is investigated and proposed for a wind turbine rotor blade. Fluid flow interaction with the proposed serrations is explored for different wind conditions. The result is supported by subsequent validation with three-dimensional numerical tools. The present work employs a statistical-numerical method to predict and optimize the shape of the serrations for maximum aerodynamic improvement. The optimal combination is found using the Taguchi method with three factors: Amplitude, wavelength, and serration thickness. The viability of the solution on an application is assessed using the Weibull distribution of wind in three selected regions. Results show that the presence of serration is capable of improving the annual power generation in all the investigated cities by up to 12%. The rated speed is also shifted from 10 m/s to 8 m/s for most configurations. Additionally, all configurations show similar trends for the instantaneous torque, where an increase is observed in pre-rated speed, whereas a decrease is noticed in the post-rated speed region. A look at the flow field pattern for the optimal design in comparison with the clean blade shows that the modified blade is able to generate more lift in the pre-stall region, while for the post-stall region, early separation and increased wake dominate the flow.

Effect of the leading-edge protuberances on the aeroacoustic and aerodynamic performances of the wind turbine airfoil

Based on the restraining effect of the leading-edge protuberances (LEPs) on flow separation, this work focuses analyzing the aeroacoustic and aerodynamic performances for the wind turbine airfoil with LEPs near the outboard region of the blades, by using the experimental testing and numerical calculation methods. The associated flow patterns for the aeroacoustic and aerodynamic performances are revealed within the pre-stall and post-stall regions. The shedding of the separation vortices enhances the instability of the laminar boundary layer, generating the aerodynamic noise from the wind turbine airfoil. The LEPs suppress the generation of the tonal noise in pre-stall region by changing the distribution and reducing the intensity of the trailing edge shedding vortices. Moreover, LEPs can improve the aerodynamic performance of the wind turbine airfoil greatly by inhibiting the flow separation at a high inflow angle of attack. As a flow control method for the wind turbine blades, LEPs will help to improve the aeroacoustic performance of the blades under normal inflow wind conditions, and the aerodynamic performance under extreme wind situations where the inflow wind changes on a large scale frequently.

Numerical Investigation on the Effect of Leading-Edge Tubercles on the Laminar Separation Bubble

The effect of leading-edge tubercles on the aerodynamic performance of E216 airfoil is studied by steady 3D numerical simulations using Transition γ−Reθ turbulance model. The investigation is carried out for the various angles of attack in the pre-stall region at Reynolds number of 100,000. Various tubercle configurations with different combinations of amplitude ranging from 2 mm to 8 mm and wavelength varying from 15.5mm to 62 mm are studied. The effect of tubercle parameters on the laminar separation bubble (LSB) is extensively studied. Improvement in the coefficient of lift (Cl) is observed for most of the tubercled models and is significant at high angles of attack. But the simultaneous increase in the drag coefficient resulted in a marginal improvement in the coefficient of lift to drag ratio (Cl/Cd) for most of the cases except for A2W62, which produced a peak value of 46.91 at AOA 6◦ which is higher than that for the baseline by 7.37%. Compared to the baseline, the magnitude of suction peak is higher along the trough and lower along the peak. The low amplitude and low wavelength tubercle model exhibited smooth surface pressure coefficient (Cp) distribution without any sign of strong LSB formation. The LSB moves upstream with the increase in amplitude and wavelength. The LSB along the trough is formed ahead of that at peak inducing three-dimensional wavy shaped LSB unlike the straight LSB as in baseline. Two pairs of counter rotating vortices are formed on the airfoil surface between the adjacent peaks at two different chord-wise locations which strongly alter the flow pattern over it.

On the performance of RANS turbulence models in predicting static stall over airfoils at high Reynolds numbers

PurposeThis paper aims to conduct, a detailed investigation of various Reynolds averaged Navier–Stokes (RANS) models to study their performance in attached and separated flows. The turbulent flow over two airfoils, namely, National Advisory Committee for Aeronautics (NACA)-0012 and National Aeronautics and Space Administration (NASA) MS(1)-0317 with a static stall setup at a Reynolds number of 6 million, is chosen to investigate these models. The pre-stall and post-stall regions, which are in the range of angles of attack 0°–20°, are simulated.Design/methodology/approachRANS turbulence models with the Boussinesq approximation are the most commonly used cost-effective models for engineering flows. Four RANS models are considered to predict the static stall of two airfoils: Spalart–Allmaras (SA), Menter’s k – ω shear stress transport (SST), k – kL and SA-Bas Cakmakcioglu modified (BCM) transition model. All the simulations are performed on an in-house unstructured-grid compressible flow solver.FindingsAll the turbulence models considered predicted the lift and drag coefficients in good agreement with experimental data for both airfoils in the attached pre-stall region. For the NACA-0012 airfoil, all models except the SA-BCM over-predicted the stall angle by 2°, whereas SA-BCM failed to predict stall. For the NASA MS(1)-0317 airfoil, all models predicted the lift and drag coefficients accurately for attached flow. But the first three models showed even further delayed stall, whereas SA-BCM again did not predict stall.Originality/valueThe numerical results at high Re obtained from this work, especially that of the NASA MS(1)-0317, are new to the literature in the knowledge of the authors. This paper highlights the inability of RANS models to predict the stall phenomenon and suggests a need for improvement in modeling flow physics in near- and post-stall flows.

A Validation Study of the Aerodynamic Behaviour of a Wind Turbine: Three-Dimensional Rotational Case

Numerical modelling and simulation of a rotating, tapered, and twisted three-dimensional blade with turbulent inflow conditions and separating flows is a challenging case in Computational Fluid Dynamics (CFD). The numerical simulation of the fluid flow behaviour over a wind turbine blade is important for the design of efficient machines. This paper presents a numerical validation study using the experimental data collected by the National Renewable Energy Laboratory (NREL). All the simulations are performed on the sequence S of the extensive experimental sequences conducted at the NASA/Ames wind tunnel with constant RPM and variable wind speeds. The results show close agreement with the NREL UAE experimental data. The CFD model captures closely the totality of the defining quantities. The shaft torque is well-predicted pre-stall but under-predicted in the stall region. The three-dimensional flow and stall are well captured and demonstrated in this paper. Results show attached flow in the pre-stall region. The separation appears at a wind speed of 10 m/s near the blade root. For V>10m/s, the blade appears to experience a deep stall from root to tip.

On the lift curve slope for rectangular flat plate wings at moderate Reynolds number

The lift coefficient for a flat plate at low angles of attack is obtained experimentally for various aspect ratios (AR ​= ​1, 2, 4, 8) and moderate Reynolds numbers (Re ​= ​40 ​× ​103 to Re ​= ​200 ​× ​103). The variation of the lift coefficient with the angle of attack in the pre-stall region is consistent with a linear slope approximation. We consider that this slope is a function of both the aspect ratio and Reynolds number. In this research, we provide a correlation that can predict the lift slope value with an average error of less than 5%. This correlation captures the idea of Prandtl’s finite wing theory and extends its application for any Reynolds number. The same correlation is tested against other literature experiments providing very accurate results even outside our range of measured AR and Re.

The influence of kinematics of blades on the flow structure in deep dynamic stall

This study considers the effect of kinematics on the aerodynamic loads and flow structure around moving blades of micro air vehicles (MAVs) in deep dynamic stall. The transversal (pure heaving) and rotational (pure pitching) motions are considered distinctly to investigate the dynamic stall. An equivalent effective angle of the attack profile is given to both motions. This method helps to figure out the influence of kinematics on flow structures when all boundary conditions and effective angles of attack profiles are the same. An experiment is conducted in fully turbulent flow at Re = 1.5×104 to avoid any transition regime in the boundary layer, and make the results relatively independent of the flow characteristics. A NACA 0012 airfoil is chosen at high reduced frequencies (k = 0.25 and 0.375) and high angles of attack to reach deep dynamic stall conditions. Additionally, time-resolved particle image velocimetry (PIV) and post-processing are used to compute the aerodynamic loads using a control-volume approach. The flow field is also reconstructed using proper orthogonal decomposition (POD) to separate the flow structures in different modes. It is shown that the kinematics can significantly influence the flow structure and aerodynamic loads. In the pre-stall region, the pure pitching motion usually produces higher lift force, while the pure heaving motion has a higher lift peak. However, in the post-stall region, the pure heaving motion usually has higher lift than the pure pitching motion. The pure heaving motion produced lower drag force than the pure pitching motion. For pure heaving motion, the POD analysis reveals there is a high-energy mode in the flow structure that helps to make the vortices more stable compared to pure pitching motion. Furthermore, the pure heaving motion adds extra kinetic energy to the boundary layer, which decelerates the reversal flow and the transfer of the separation point on suction side of the airfoil.

Influence of tubercles’ spanwise distribution on swept wings for unmanned aerial vehicles

In this work, a 3D numerical study on the influence of the spanwise distribution of tubercles on a unmanned aerial vehicle wing is presented. The idea of using tubercles in aeronautics comes from the humpback whale (Megaptera novaeangliae) which has a characteristic flipper, with a spanwise scalloped leading edge, creating an almost sinusoidal shape, consisting of bumps called tubercles. The whale uses this layout in order to achieve high underwater maneuverability. Early experimental research showed a great potential in enhancing the 3D aerodynamic characteristics of a wing. Most of the existing experimental results concern infinite wings (2D) models and are accompanied with substantial loss in lift and increase in drag in pre-stall region. On the other hand, 3D finite models have displayed a better overall aerodynamic performance (increased lift and moment, but also, decreased drag). At a range of Reynolds number between 500,000 and 1,000,000 (based on the mean chord of the flipper), tubercles act as virtual fences, introducing a pair of counter rotating vortices that delays the stall of the flipper, a phenomenon that the whales exploit to perform sharp turns and catch their prey. The aforementioned Reynolds number range is the same as the operational Reynolds number for typical unmanned aerial vehicles. To assess the influence of the tubercles installation on UAV wings, a full 3D computational study is carried-out with the use of CFD tools which at a first phase are validated and calibrated with the available literature experimental data. Then, computations are performed for different spanwise tubercles distributions. The results show that there is a noticeable potential on controlling the flow on the wings of a UAV operating in a Reynolds number range between 500,000 and 1,000,000 (based on UAV’s wing mean chord), which can lead to an aerodynamic performance and efficiency increase.

Experimental and numerical study of laminar separation bubble formation on low Reynolds number airfoil with leading-edge tubercles

The present work reports the effect of leading-edge tubercles on aerodynamic performance and flow features of a cambered airfoil E216 at a Reynolds number of 100,000 and at various angles of attack in the pre-stall regime. Amplitude values of 2 mm, 4 mm and 8 mm and wavelength values of 15.5 mm, 31 mm and 62 mm are used for both experimental and simulation studies. The Transition-SST RANS model is used to simulate transition phenomenon (laminar separation bubble) and three-dimensional flow features over the airfoil. Wind tunnel experimental results are used for the performance analysis and the validation of the simulation methodology. The experimental values of $$C_\mathrm{l}$$ and $$C_\mathrm{d}$$ are 1.37 and 0.081, respectively, at a stall angle of $$12^{\circ }$$ for the plain airfoil. The experimental results show that the lift generated by tubercled airfoils is higher than that produced by the plain airfoil in the pre-stall region but lower at the stall angle. A maximum benefit of 4.51% in $$C_\mathrm{l}$$ is obtained for the tubercled airfoil with the highest amplitude (8 mm) and wavelength (64 mm) at $$6^{\circ }$$ angle of attack. A higher $$C_\mathrm{d}$$ is observed for all the tubercled airfoils than for the plain one. The simulation is mainly carried out to study the flow structure. Simulation results indicate the presence of laminar separation bubbles on the plain airfoil with a straight separation and reattachment line parallel to the trailing edge. The tubercles considerably altered the laminar separation bubble formation and the flow structure. A sinusoidal laminar separation bubble is formed on the tubercled airfoils with reduced bubble length. The laminar separation bubble along the trough is formed ahead of that at peak. Two pairs of counter-rotating vortices are formed on the airfoil surface along the trough at two different chord-wise locations which strongly alter the flow pattern over it. Prandtl’s secondary flow of the first kind is the key reason for the vortex formation.

Investigation on the effect of leading edge tubercles of sweptback wing at low reynolds number

Aerodynamic efficiency of an airplane wing can be improved either by increasing its lift generation tendency or by reducing the drag. Recently, Bio-inspired designs have been received greater attention for the geometric modifications of airplane wings. One of the bio-inspired designs contains sinusoidal Humpback Whale (HW) tubercles, i.e., protuberances exist at the wing leading edge (LE). The tubercles have excellent flow control characteristics at low Reynolds numbers. The present work describes about the effect of tubercles on swept back wing performance at various Angle of Attack (AoA). NACA 0015 and NACA 4415 airfoils are used for swept back wing design with sweep angle about 30°. The modified wings (HUMP 0015 A, HUMP 0015 B, HUMP 4415 A, HUMP 4415 B) are designed with two amplitude to wavelength ratios (η) of 0.1 & 0.24 for the performance analysis. It is a novel effort to analyze the tubercle vortices along the span that induce additional flow energy especially, behind the tubercles peak and trough region. Subsequently, Co-efficient of Lift (CL), Co-efficient of Drag (CD) and boundary layer pressure gradients also predicted for modified and baseline (smooth LE) models in the pre & post-stall regimes. It was observed that the tubercles increase the performance of swept back wings by the enhanced CL/CD ratio in the pre-stall AoA region. Interestingly, the flow separation region behind the centerline of tubercles and formation of Laminar Separation Bubbles (LSB) were asymmetric because of the sweep.

Investigation on Performance of Compressor Cascade with Tubercle Leading Edge Blade

Abstract In order to improve compressor performance using a new design method, which originates from the fins on a humpback whale, experimental tests and numerical simulations were undertaken to investigate the influence of the tubercle leading edge on the aerodynamic performance of a linear compressor cascade with a NACA 65–010 airfoil. The results demonstrate that the tubercle leading edge can improve the aerodynamic performance of the cascade in the post-stall region by reducing total pressure loss, with a slight increase in total pressure loss in the pre-stall region. The tubercles on the leading edge of the blades cause the flow to migrate from the peak to the valley on the blade surface around the tubercle leading edge by the butterfly flow. The tubercle leading edge generates the vortices similar to those created by vortex generators, splitting the large-scale separation region into multiple smaller regions.

Effect of surface blowing on aerodynamic characteristics of tubercled straight wing

Recent research proves that wings with leading-edge tubercles have the ability to perform efficiently in post-stall region over the conventional straight wing. Moreover, the conventional straight wing outperforms the tubercled wing at a pre-stall region which is quintessential. Even though tubercled wing offers great performance enhancement, because of the complexity of the flow, the trough region of the tubercled wing is more prone to flow separation. Henceforth, the present paper aims at surface blowing – an active flow control technique over the tubercled wing to enhance the aerodynamic efficiency by positively influencing its lift characteristics without causing any additional drag penalty. Flow parameters like blowing velocity ratios and the location of blowing were chosen to find the optimised configuration keeping the amplitude and frequency of the leading-edge tubercles constant as 0.12c and 0.25c respectively. Numerical investigations were carried out over the baseline tubercled wing and tubercled wing with surface blowing at various blowing jet velocity ratios 0.5, 1 and 2 over four different chordwise locations ranging from 0.3c to 0.8c. The results confirm that blowing at various x/c with different blowing velocity ratios performs better than the conventional tubercled wing. Comparatively, blowing velocity ratio 2 at 0.3c shows peak performance of about 28% enhancement in the lift characteristics relative to the baseline model. Particularly, in the pre-stall region, 25–50% increase in aerodynamic efficiency is evident over the tubercled wing with surface blowing compared with the baseline case. Additionally, attempts were made to delineate the physical significance of the flow separation mechanism due to blowing by visualizing the streamline pattern.

A Development and Assessment of Variable-Incidence Angle Vortex Generator at Low Reynolds Number of ~ 5×104

The aerodynamic benefit for conventional vortex generator (VG) is often counterbalanced by the appearance of parasite drag. An immovable installation similar to a fixture also limited its application. To overcome those issues, this paper proposes a variable-incidence-angle vortex generator (VIVG). Counter-rotated miniature gears with a single rack-pinion system adjust the incidence angle of the VIVG, thereby precisely control mixing flux at boundary layer interface with minimizing the parasite drag. The variable incidence angle of the VIVG was then examined to evaluate the applicability of the VIVG at low Reynolds number. The VIVG was mounted on a NACA 0015 airfoil, and a low-turbulence blowing type wind tunnel was employed. We found that the VIVG effectively eliminated laminar separation bubbles, and suppressed separation at Reynolds number of 5.4 × 104; excessive lift production at low Reynolds number became similar to a theoretical value of potential flow (CL = 2πα). It was also found that the VIVG can reduce the drag in the pre-stall region at the low Re with small incidence angles, providing a noticeable increment of the lift-to-drag ratio. The large incidence angle of VIVG was also useful both to extend the stall point and to produce higher lift force with reasonable efficiency. These clearly indicate that the VIVG is applicable for performance improvement of aerodynamic devices operated in low Reynolds number flow fields.

Lift distribution of washout twist morphing MAV wing

Micro Air Vehicle, or also commonly known as MAV, is a miniature aircraft that has been gaining interest in the industry. MAV is defined as a flying platform with 15cm wingspan and operates at a speed of around 10m/s. Recently, MAV has been exposed with the latest development and link towards the biologically-inspired designs such as morphing wing. Twist morphing wing is one of the latest MAV wing design developments. The application of Twist Morphing (TM) on MAV wing has been previously known to produce better aerodynamic performance. Previous study in washin TM wing has shown a promising possibility of generating higher lift force. Despite the benevolent performance exhibited by the washin TM wing, the lift distribution for the washout type of TM MAV is relatively unknown and still open to be explored. This is probably due to the lack of experimental test rig to produce the washout twist morphing motion on the MAV wing. Therefore, this research aims to produce a special test rig for washout TM wing that is compatible for wind tunnel experimental testing. By using the special test rig, the experimental investigation on the lift performance of washout TM MAV wing can be done. Based on the wing deformation results, it clearly shows that the proposed test rig is capable to produce up to 19.5mm tip deflection at the morphing point, which is also resulting in a significant morphing motion. Higher morphing force induces larger morphing motion. Based on the lift distribution results, they show that the morphing motion has significantly affected the overall lift distribution on the MAV wing. The morphing motion on TM wing has produced at least 17.6% and 5.33% lower CL and CLmax magnitude, respectively, with the membrane wing especially at the pre-stall region. However, the TM wing is still able to maintain the stall angle similar to the baseline wing at αstall= 31°. By maintaining high αstall value with lower CL and CLmax magnitude, TM wing produces more agility for the MAV maneuverability that will be useful for indoor mission or obstacle avoidance flight.