Asymmetric Inflow Research Articles

Near wake evolution of a tidal stream turbine due to asymmetric sheared turbulent inflow with different integral length scales

Tidal stream turbines deployed at highly energetic open water sites are subjected to sheared inflow in the rotor plane. The inflow shear is expected to cause asymmetric loading on the rotor blades and affect the downstream wake. In the current study, two different turbulent inflow conditions, static-high shear and dynamic shear, were generated via an active-grid turbulence generator. A 1:20 scaled three-bladed horizontal axis tidal turbine model was tested in those conditions. The results were compared to a quasi-laminar case with no imposed turbulence or shear. The results show that the high shear reduces the average performance, with a drop of up to 16% in the optimal power coefficient. Besides, the shear profiles increase torque fluctuations and induce significant differences in wake hydrodynamics between the high-speed (upper) and low-speed (lower) regions. The large integral length scales further enhance the load fluctuations perceived by the rotor but have a negligible effect on the mean wake field quantities. The wake recovery was found to be ∼2 to 4 times faster in the upper half region than in the lower region in the near wake. The lower half region featured a faster breakdown of tip vortex structure and a rapid drop of swirl number, a phenomenon conjectured to be a consequence of the strong turbulence intensities and Reynolds stresses in the lower half region. The sheared turbulent inflow also results in a very intensive energy redistribution process towards large-scale, low-frequency motions, which is important to the downstream turbines.

Investigation of wind turbine unsteady aerodynamics and trailing-edge noise characteristics under wake steering

In wake steering strategy, the shaft of an upstream wind turbine is yawed to deflect the wake and decrease the wake-swept area of the downstream wind turbine rotor. This intentional yaw misalignment increases the output power of the downstream wind turbine at the expense of some loss of upstream wind turbine power, consequently increasing the total wind farm power. However, the asymmetric non-uniform inflow into the downstream wind turbine due to the deflected wake causes unsteady aerodynamic loads and affects the wind turbine noise characteristics. In this study, the unsteady vortex lattice method coupled with the curled wake model is used to predict the unsteady aerodynamics of a downstream wind turbine in wake steering. Based on the unsteady aerodynamic results, the trailing-edge noise characteristics are predicted by a semi-empirical method. The impact of wake steering on trailing-edge noise level and amplitude modulation is evaluated. The results show that the asymmetric non-uniform inflow due to wake steering increases the amplitude modulation of the downstream wind turbine.

Improvement of energy performance of a two-way pumping station based on controllable diffusion technology

Energy performance is a crucial parameter for evaluating a two-way pumping station. However, the sharp decrease in efficiency within overload flow rates presents a challenge. To address this issue, the controllable diffusion technology (CDT) is developed based on asymmetric inflow theory. Transient numerical simulation is carried out under five different distortion angles. The energy performance and entropy production dissipation before and after the application of CDT are comprehensively studied. (a) First, CDT successfully improves the operation efficiency within the overload flow rate range. The reverse distortion has a better improvement effect than the syntropic distortion. (b) Second, under asymmetric inflow conditions, the reduction in the axial velocity causes the best-efficiency point to deviate toward the overload flow rate. This leads to an increase in the total entropy production (TEP) within 0.7Qdes–0.95Qdes, followed by a decrease within 1.05Qdes–1.3Qdes. (c) Third, the CDT-induced horizontal velocity causes a mismatch between the impeller inflow angle and blade placement angle, which leads to uneven spatial distribution of the total entropy production rate inside the pumping station.

Hydraulic characteristics and flow trajectories under two-sided asymmetric inflow conditions for a deep storage tunnel system

Deep storage tunnels (DSTs) are used in densely urbanized areas to relieve stormwater collection systems, thereby reducing urban floods and runoff pollution, due to their substantial storage capacity. The computation of the hydraulic characteristics and flow trajectories of DSTs under rapid filling scenarios can help to predict sediment deposition and pollutant accumulation associated with the stored runoff, as well as the likelihood of operational problems, such as excessive surging. However, such assessments are complicated by various inflow scenarios encountered in tunnel systems during their operation. In this study, the Suzhou River DST in China is selected as a study case. Particles were tracked, and hydraulic analysis was conducted with scaled model experiments and numerical models. The flow field, particle movement, air‒water phase, and pressure patterns in the DST were simulated under various one- and two-sided inflow scenarios. The results showed that with regards to the design conditions involving two-sided inflows, flow reversals occurred with stepwise increases in the water surface and pressure. In contrast, this phenomenon was not observed under the one-sided inflow scenario. Under the asymmetric two-sided inflow scenarios, water inflows led to particle accumulation near the shaft, reducing the received inflows. However, under the symmetric inflow conditions, particles were concentrated near the middle of the tunnel. Compared to those under the symmetric inflow scenario, asymmetric inflow caused surface wave and entrapped air reductions. This study could provide support for regulation of the inflow of the Suzhou River DST and for prediction of sediment and pollutant accumulation.

Acoustic signature of sUAS rotors undergoing edgewise forward flight

This presentation shares preliminary experimental results from a new sUAS rotor test rig installed in UNSW’s Anechoic Wind Tunnel (UAT). This new test rig allows acoustic and aerodynamic performance testing of small drone-scale rotor blades under edgewise forward flight conditions at a range of shaft angles. The study of sUAS rotors under edgewise forward flight presents asymmetric inflow to the rotor and unsteady loading on the blades themselves, with different flow conditions experienced by the advancing and retreating rotor blades. This means the acoustic signature of a rotor undergoing edgewise flight is significantly changed compared to static thrust or axial flight conditions of drone rotors or propellers. This presentation aims to outline changes to the acoustic signature of a collection of conventional off the shelf (COTS) rotor and propeller designs between static, axial flight and edgewise flight conditions, coupling this with rotor performance metrics.

Numerical study of the effects of excess air ratio on passive pre-chamber jet performance and ignition mechanism

Pre-chamber (PC) ignition is a promising lean-burn technology to improve the efficiency of spark ignition (SI) engines while achieving ultra-low NOx emissions. However, the significant effects of the excess air ratio (λ) on the PC jet performance and ignition mechanism were still not fully unraveled. The current study numerically investigated the jet characteristics and combustion behaviors of a narrow-throat PC with two rows of orifices on a passive PC engine fueled with methane. The numerical model was validated extensively by the pressure, heat release rate, and natural flame luminosity (NFL) imaging of the PC flame jet. A detailed comparison of the NFL images of the jets and the simulated flame iso-faces presented excellent matching in the flame jet penetration and propagation process. The results reveal that the λ = 0.9 case has the best jet performance, but it doesn’t lead in every jet characteristic. For instance, the jet temperature is highest under λ = 1.0, and OH concentration is most under λ = 1.1. The transition from cold jet to flame jet produces noticeable jet non-uniformity, which is reported for the first time. This observation can be remarked as a more accurate indication of the initiation of pre-chamber flame jet discharge. The asymmetrical mixture inflow from the main chamber produces asymmetrical turbulent kinetic energy (TKE) and temperature distributions; these result in different flame propagation in the PC, jet non-uniformity, and varied stages of jet discharge. The upper jets are quenched in every case because of the much higher TKE, while the lower jets don’t present quenching when the λ ranges from 0.9 to 1.3; especially, the λ = 1.1 case has the best ignition performance for its most OH radicals. The “jet ignition regime”, in which flame quenching takes place, results in highly non-uniform flame propagation and low flame propagation speed. The ultra-rich case shows more signs of jet ignition and thus exhibits worse jet performance than the lean cases. This study uncovers the mechanisms and the optimal λ value for the pre-chamber ignition of the main chamber charge, providing valuable guidance for PC design.

Numerical and experimental investigation of irreversible energy losses in a two-stage radial turbine under asymmetric inflow conditions

In a two-stage turbocharger, the coupling between stages and the structure of the inter-stage duct may lead to severe flow distortions, which have a destructive impact on turbine performance. In this paper, the aerodynamics and energy loss mechanisms of two-stage turbines matched with a V-6 diesel engine are experimentally and numerically investigated. To reveal the formation mechanism of the asymmetric inter-stage flow, the vortex transportation in the high-pressure turbine is first analyzed. Entropy generation analysis is applied to quantify the irreversible losses while considering the coupling influence of the asymmetric inflow conditions, and two types of curved inter-stage ducts are studied. The sources of the dominant irreversible losses are revealed and origin of the corresponding energy loss is localized. The results show that the entropy generation rates associated with viscous dissipation, turbulent dissipation, and heat conduction account for about 30% each in the low-pressure turbine. Compared to uniform inflow conditions, the entropy generation rates increase by an average of 43.8%, 196.9%, and 19.2%, respectively under asymmetric inflow conditions. The pivotal turbulent dissipation is primarily concentrated in the inter-stage duct, the impeller inlet, and the volute tongue. The peak value for the difference in the cumulative entropy generation rates from turbulent dissipation is mainly caused by the mixing of the leakage vortex and the separation flow. The novelty of the present study lies in revealing the source of irreversible losses in two-stage turbines, which may provide a fundamental basis for the optimal design of a two-stage turbocharger.

Dynamics of chaotic waterwheel model with the asymmetric flow within the frame of Caputo fractional operator

The chaotic waterwheel model is a mechanical model that exhibits chaos and is also a practical system that justifies the Lorenz system. The chaotic waterwheel model (or Malkus waterwheel model) is modified with the addition of asymmetric water inflow to the system. The hereditary property of the modified chaotic waterwheel model is analyzed to determine the system’s stability and identify the parameter that contributes to the stability We also examine the factor that leads to the bifurcation. We determine the well-posed nature of the modified system. The modified chaotic waterwheel model is defined with the Caputo fractional operator. The existence and uniqueness, boundedness, stability, Lyapunov stability, and numerical simulation are studied for the modified fractional waterwheel model. The bifurcation parameter and Lyapunov exponent are examined to study the chaotic nature of the system with respect to the fractional order. The nature of the system is captured with the help of the efficient numerical approach Adams–Bashforth–Moulton Method. The numerical approach demonstrates that the chaotic nature of the modified chaotic waterwheel is changed into unstable nature, which could further reduce to the stable case with suitable values of the parameter. This analysis is justified with the help of Lyapunov exponent. We consider irrational order (π,e) in the present work to illustrate the reliability of fractional order.

Integrated design and analysis of inlet and missile with two side layout

Abstract Based on the flow field characteristics of the missile body, an integrated design method for missile and inlet with two side layout is proposed under asymmetric inflow. The result of numerical simulation shows that shock waves hit on cowl lip on the symmetry plane at the design condition, which verifies the method of integrated design. And the flow characteristics of inlet under the influence of the missile body are analyzed. Under the influence of asymmetric incoming flow and missile body, the first shock wave surface of the two-dimensional inlet presents the characteristics of a three-dimensional concave surface, and there is a pair of asymmetric vortex structures in the inner flow path. Finally, a bleed cavity of self-adaptively adjusting bleeding by vortex is proposed to improve the performance of inlet and broaden the inlet start and attack angle boundary. The minimum Mach number of the inlet start is reduced from 2.8 to 2.3 at ɑ = 6° and the maximum attack angle of inlet start is widened from ɑ = −1° to ɑ = 3° at Ma = 2.1.

Flow Characteristics and Anti-Vortex in a Pump Station with Laterally Asymmetric Inflow

In a laterally asymmetric intake pumping station, the flow direction in the forebay is not consistent with flow in the intake channel. Thus, the adverse flow patterns, such as bias flow, large-scale vortex and asymmetric flow occur frequently in the forebay and sump. Based on the Reynolds-averaged Navier-Stokes (RANS) equation and the RNG k-ε turbulence model, a recent flow pattern in a laterally asymmetric intake pumping station was numerically simulated and analyzed, and effective vortex elimination measures were proposed. For the original scheme, seriously biased flow combined with large-scale vortices were observed in the forebay and several vortices occurred in the sump. To suppress the clash inflow in the south and north intake channel, the “straight diversion pier + curved wing wall” and “straight diversion pier + curved wing wall + V-shaped diversion pier” were installed separately. The” symmetrical 川-shaped diversion pier” and “symmetrical 川-shaped diversion pier + circular column” was utilized to eliminate the bias flow and large-scale vortices in the forebay. Finally, the “three- sectional diversion pier”, “three- sectional diversion pier + triangle column” and “three- sectional diversion pier + triangle column + straight back baffle” was applied to decrease the vortex and asymmetric flow near the suction pipe of the sump. By attaching the rectification measure schemes in the intake channel and the forebay, the bias flow and large-scale vortex in the forebay were suppressed to varying degrees. The schemes significantly reduced the recirculation coefficient and greatly reduced the recirculation volume. By utilizing the vortex elimination measures in the sump, the vortex and asymmetric flow basically disappeared, the velocity distribution tended to become more uniform, and the flow rate distinction of each pump was smaller. The outcome can be used to provide a reference and basis for the improvement of flow pattern in similar laterally asymmetric intake pump stations.

Essential Dynamics of the Vertical Wind Shear Affecting the Secondary Eyewall Formation in Tropical Cyclones

Abstract This study investigated the effects of vertical wind shear (VWS) with varying magnitudes on secondary eyewall formation (SEF). It turns out that weak-to-moderate VWS advances the timing of SEF. Strong VWS, however, is unfavorable for SEF in our idealized simulations. VWS affecting SEF mainly lies on its influence on the outer rainbands (ORBs). Under weak-to-moderate VWS, ORBs develop more quickly in the downshear side and have distinct stratiform features in the upshear-left quadrant. The asymmetric inflow associated with the stratiform cooling descends into the boundary layer, reinforcing radial convergence at the radially inward side of ORBs. The radial convergence enhances the low-level convection, resulting in strengthened boundary layer inflow and accelerated low-level tangential wind jet. A budget analysis reveals that tangential advection extends a tangential wind jet farther downwind, forming supergradient winds above the boundary layer in the upshear-right quadrant. As the ORBs propagate into the upshear-right quadrant, the pre-existing supergradient winds enhances the low-level convection, facilitating the closing of the secondary convective ring. The evolution in the upshear side exhibit quadrant-dependent interactions between ORBs and boundary layer. Following that, azimuthal-mean tangential wind acceleration becomes visible, forming the secondary tangential wind maximum. Under strong VWS, the storm is weakened and the boundary layer in the upshear-left quadrant is invaded by low-entropy air, resulting in decreased conditional instability and low-level thermal buoyancy. The decreased stratiform precipitation due to weakened convective activity in the upshear-left quadrant prevents the upshear propagation of ORBs and thus is unfavorable for SEF.

Investigating the Mixture Quality in Multi-Injector Burner Systems—Part I: Experimental Setup

Abstract A new approach to calculate the mixture statistics in multi-injector burner (MIB) systems from a single injector database is presented in the paper. In such systems, the mixture quality is highly sensitive to the flowrate and the skewness of the inflow velocity profile. To determine the mixture fraction statistics from these two parameters for a particular injector in a multi-injector configuration, output-based proper orthogonal decomposition (O-POD) is suggested using results from Reynolds-averaged Navier Stokes (RANS)–computational fluid dynamics (CFD) as the observable. The O-POD mixing database is determined experimentally from two setups: First, the mixture quality in a single injector at ideal inflow conditions is studied. Then the same injector type is investigated in a generic MIB system. To characterize the mixture quality, the mixing probability mass function (PMF) at the injector exit is measured by means of laser-induced fluorescence (LIF) and high speed imaging. The data obtained for both the single injector under ideal inflow and the MIB are presented. These studies of the mixture behavior reveal that an asymmetric inflow velocity profile leads to a significant increase of unmixedness, which is seen as a negative skewness of the mixing PMFs. This effect becomes stronger at higher momentum flux density ratios due to the higher penetration depth of the fuel jets. The application of the O-POD to the database shows that the PMF can be accurately modeled with only three modes.

Physiologic Flow Diversion Coiling Technique for Wide-Necked Aneurysms with an Asymmetric Bidirectional Flow at the Aneurysm Neck.

Wide-necked aneurysms in the circle of Willis (CoW) are prone to recur due to reciprocal bidirectional flow. We present a novel concept of coil embolization to prevent recurrence that uses physiologic flow diversion at the CoW. We enrolled 14 patients (15 aneurysms) who underwent aneurysm coiling for wide-necked aneurysms with asymmetric bidirectional inflow into the aneurysm. Four patients had recurrent aneurysms after coiling. The concept of physiologic flow diversion included obliterating antegrade flow into the aneurysm sac as well as opposite CoW flow by performing compact coil packing with intentional protrusion out of the aneurysm neck to the communicating part. Fifteen aneurysms, including 4 recurrent aneurysms, in an anterior communicating artery (n=7), posterior communicating artery (n=5), and tip of the basilar artery (n=3) were treated with coil embolization (n=10) and stent-assisted coiling (n=5). All aneurysms had a wide neck, and the mean largest diameter was 9.0 mm. The mean packing density was 45.1%. Twelve aneurysms were completely occluded, and 3 aneurysms had tiny residual neck remnants. There was neither a neurological event nor recurrence during the mean 12.5 months of follow-up. Wide-necked aneurysms at the CoW tend to recur. As a strategy to prevent a recurrence, physiologic flow diversion can be an option in treating wide-necked aneurysms in the CoW.

Understanding loss generation mechanisms in a centrifugal pump using large eddy simulation

Water pumps are amongst the most frequently used turbomachines, which consume about 9% of the global energy production. This paper provides insight on the loss generation mechanisms in inline centrifugal pumps operating under realistic conditions through a detailed analysis based on large eddy simulation (LES). The equations for the resolved, sub-grid and wall entropy generation terms are derived using the LES filtering and Smagorinsky-Lilly formalism. Specific exergy is calculated at the grid points. Entropy generation and exergy transfer within the flow domain are visualised to highlight the loss generation mechanisms within the pump. Results show that there is a strong component interaction. The double-bended inlet pipe initiates Dean-vortices at the eye of the impeller. This asymmetric inflow coupled with the disturbances at the cut-off cause a non-uniform flow through the blade passages. Other drivers of the asymmetrical loading of the blade passages are high leakage and unsteady and asymmetrical mass and exergy transfer between the dead zone. The paper also investigates the effect of the grid resolution on the first and second order statistics of the flow field and its turbulent characteristics. A thorough evaluation of the discretisation error is presented to provide a measure for the required grid density and demonstrate the extent and impact of the temporal and spatial discretisation error in centrifugal turbomachinery.

Entropy production analysis for energy dissipation of a vertical mixed-flow pump device under asymmetric inflow conditions

To investigate the influence of the inflow angle on the hydraulic loss and internal flow fields of a vertical mixed-flow pump device, unsteady numerical simulations were performed under different inflow angles ( θ = 0°, 10°, 20°, and 30°). The calculation results were validated using an external characteristic test at an inflow angle of 0°. The entropy production theory was applied to analyse the energy loss and dissipation rate distribution in a vertical mixed-flow pump device under different inflow angles. Influenced by asymmetric inflow, the design point of the external characteristics deviated towards the overload flow rate, and the maximum deviations were obtained under 1.2 Q des, whereas the influence of the inflow angle on the internal flow fields was the most significant under the part-load flow rate. When the inflow angle increased from 0° to 30°, the total entropy production in the pump device increased by 18.35% under 0.6 Q des, and indirect dissipation accounted for the largest proportion. The internal flow patterns in the impeller and guide vane were also distorted by asymmetric inflow. The indirect dissipation rate on the suction side of the impeller blade, interface between the impeller and diffuser, and pressure side of the guide vane increased significantly with an increase in the inflow angle. To restrain the influence of asymmetric inflow, it is of great significance to optimise the hydraulic design structure of the inflow runner. In this study, a middle spacer pier was used to improve the operational efficiency of the pump device.

Influence of asymmetric inflow on the transient pressure fluctuation characteristics of a vertical mixed-flow pump

In order to investigate the influence of asymmetric inflow on the internal flow fields of a vertical mixed-flow pump, numerical simulation of unsteady flow was carried out under four inflow angles ( θ = 0°, 10°, 20°, and 30°). The reliability of the calculation results was validated through an external characteristic experiment. The fluctuation value of the pressure was defined to obtain the transient pressure fluctuation intensity distribution. Three monitoring points were arranged to compare pressure fluctuation characteristics under different inflow angles. The results suggested that the increase in the inflow angle caused the design operation points to deviate to the over-load flow rate. When the inflow angle increased from 0° to 30°, the axial velocity distribution coefficient and weighted average angle at the inflow runner outlet both decreased. The overall transient pressure fluctuation intensity inside the impeller increased, especially on the pressure side of the blade. Additionally, the transient pressure fluctuation intensity on the pressure side of the guide vane also increased significantly. As a result, the amplitude of pressure fluctuation at the dominant frequency of each monitoring point increased. Relatively speaking, the negative influence of asymmetric inflow on the operational stability of the pumping station was further extended under the part-load flow rate.

Relativistic Asymmetric Magnetic Reconnection.

We derive basic scaling equations for relativistic magnetic reconnection in the general case of asymmetric inflow conditions and obtain predictions for the outflow Lorentz factor and the reconnection rate. Kinetic particle-in-cell simulations show that the outflow speeds as well as the nonthermal spectral index are constrained by the inflowing plasma with the weaker magnetic energy per particle, in agreement with the scaling predictions. These results are significant for understanding nonthermal emission from reconnection in magnetically dominated astrophysical systems, many of which may be asymmetric in nature. The results provide a quantitative approach for including asymmetry on reconnection in the relativistic regime.

Effects of Varying Mass Inflows on Star Formation in Nuclear Rings of Barred Galaxies

Abstract Observations indicate that the star formation rate (SFR) of nuclear rings varies considerably with time and is sometimes asymmetric rather than being uniform across a ring. To understand what controls temporal and spatial distributions of ring star formation, we run semiglobal, hydrodynamic simulations of nuclear rings subject to time-varying and/or asymmetric mass inflow rates. These controlled variations in the inflow lead to variations in the star formation, while the ring orbital period (18 Myr) and radius (600 pc) remain approximately constant. We find that both the mass inflow rate and supernova feedback affect the ring SFR. An oscillating inflow rate with period Δτ in and amplitude 20 causes large-amplitude (a factor of ≳5), quasi-periodic variations of the SFR when Δτ in ≳ 50 Myr. We find that the time-varying interstellar medium (ISM) weight and midplane pressure track each other closely, establishing an instantaneous vertical equilibrium. The measured time-varying depletion time is consistent with the prediction from self-regulation theory provided the time delay between star formation and supernova feedback is taken into account. The supernova feedback is responsible only for small-amplitude (a factor of ∼2) fluctuations of the SFR with a timescale ≲40 Myr. Asymmetry in the inflow rate does not necessarily lead to asymmetric star formation in nuclear rings. Only when the inflow rate from one dust lane is suddenly increased by a large factor do the rings undergo a transient period of lopsided star formation.

Spatial evolution of magnetic reconnection diffusion region structures with distance from the X-line

We report Magnetospheric Multiscale four-spacecraft observations of a thin reconnecting current sheet with weakly asymmetric inflow conditions and a guide field of approximately twice the reconnecting magnetic field. The event was observed at the interface of interlinked magnetic field lines at the flank magnetopause when the maximum spacecraft separation was 370 km and the spacecraft covered ∼1.7 ion inertial lengths (di) in the reconnection outflow direction. The ion-scale spacecraft separation made it possible to observe the transition from electron-only super ion-Alfvénic outflow near the electron diffusion region (EDR) to the emergence of sub-Alfvénic ion outflow in the ion diffusion region (IDR). The EDR to IDR evolution over a distance less than 2 di also shows the transition from a near-linear reconnecting magnetic field reversal to a more bifurcated current sheet as well as significant decreases in the parallel electric field and dissipation. Both the ion and electron heating in this diffusion region event were similar to the previously reported heating in the far downstream exhausts. The dimensionless reconnection rate, obtained four different ways, was in the range of 0.13–0.27. This event reveals the rapid spatial evolution of the plasma and electromagnetic fields through the EDR to IDR transition region.

The Wealthy World's Open-Economy from FDI Inflow Is a Real Thing: Malaysia's Experience

Fiscal policy is one of the popular instruments used by government to provide balance to growth in the national economy and market. In Malaysia’s context, fiscal policy is implemented using such as the annual budgets, Malaysia Plans, and multiple stimulus packages aimed at boosting Malaysia’s economy especially during the recent lock down which has threatened to cause an economic crisis due to the Covid-19 pandemic. Additionally, one of the Malaysian Government’s biggest spending using fiscal policy is its development expenditure, and tax is one of the largest contributions used to support this development expenditure. In order to attract investors to Malaysia, critical features such as benefits, facilities, and social welfare have been designed by decision-makers in each formulated policy. Initiatives such as inter-governmental forums, trade agreements and discussions are platforms that can be used to share and respond to economic problems. However, the existence of competition and foreign policy have become major challenges to the country’s efforts to attract investors. Therefore, the aim of this study is to investigate the relationship between Malaysia’s federal government development expenditure with foreign direct investment (FDI) inflow, as well as the country’s openness towards investment. The two dimensions of asymmetric FDI inflow were analysed to see how they react to government expenditure from 1970 until 2019 using the Linear and Nonlinear Autoregressive Distributed Lag method. Findings from the Nonlinear Autoregressive Distributed Lag Model (NARDL) model indicated that FDI has a positively significant effect on fiscal accumulation for development expenditure. In conclusion, increases in government expenditure increase FDI inflow into Malaysia in both the short- and long-run. Hence, government development expenditure behaviour represents accelerating economic growth in the Malaysian context, and it is proven to have a significant impact towards economic growth in the long-run. This study contributes to empirical literature on the relationship between federal government development expenditure and FDI inflow, particularly the effect of openness to investment into a developing country towards economic growth in the long- run.