Thrust Enhancement Research Articles

A Novel and More Efficient Oscillating Foil for Wave-Driven Unmanned Surface Vehicles.

In the wave-driven unmanned surface vehicles (WUSVs), oscillating-foils are the most straightforward and widely used wave energy conversion mechanism, like the wave glider. However, WUSVs usually sail slowly compared with other types of USVs. Improving the thrust of the oscillating foil to increase its speed can help WUSVs improve their maneuverability and shorten the completion of ocean missions. This paper proposed a novel method to enhance oscillating foils’ thrust force using asymmetric cross-section shape and asymmetric oscillating motion. The thrust enhancement effect is verified by CFD simulation and pool experiment. The experimental results show that the asymmetric wing can enhance the propulsive force by at least 13.75%. The speed enhancement of WUSVs brought by this enhanced thrust is at least 7.6%, which has also been verified by simulation and sea experiment. The asymmetric foil only needs to make low-cost modifications on the traditional rigid symmetric foil to achieve the desired thrust enhancement effect.

Propulsive performance of a pitching foil in a side-by-side arrangement with auxiliary pitching foil

A two-dimensional computational study is performed in the present work to simulate two NACA 0012 (National Advisory Committee for Aeronautics) airfoils pitching in a side-by-side configuration at Reynolds Number (Re) 12,000. An auxiliary airfoil with a smaller size is used to enhance the efficiency of the main airfoil. The thrust and lift coefficients of the main airfoil are quantified and compared with an isolated pitching airfoil for a range of reduced frequencies (k=1 to 8) and phase differences (Φ=0°to 180°) between the airfoils. The thrust force increases gradually with a maximum enhancement at an intermediate phase difference (Φ) between the airfoils and decreases further. The simulations cover three main flow regimes depending upon the vortex structure shed by the airfoils, i.e. (i) when both airfoil shed von Kármán (KV) vortex street (ii) auxiliary airfoil sheds von Kármán whereas main airfoil sheds reverse von Kármán (RKV) vortex street (iii) both airfoil sheds reverse von Kármán vortex street. The numerical results reveal that an auxiliary airfoil significantly changes the main airfoil’s hydrodynamic characteristics compared to an isolated airfoil. Maximum thrust enhancement of 23% and maximum efficiency enhancement of 49.2% are obtained compared to an isolated airfoil. The phase difference significantly impacts the propulsive efficiency of auxiliary foil, whereas its influence is marginal on the main foil. The interaction of different wake structures shed by the auxiliary, and the main airfoil leads to the formation of the deflected jet. The jet deflection and wake width are quantified to understand the influence of an auxiliary airfoil in a side-by-side configuration with the main airfoil. The finding of this study is expected to provide new insight for developing and enhancing the performance of hydrodynamic propulsive systems by adding an auxiliary airfoil.

The thrust enhancement for SDBD with nanostructured TiO2 films

Design requirements of the structural features, the material properties, and the processing capabilities are hard to be satisfied in nanotechnologies simultaneously. In this paper, TiO2 nanoparticles that are chemically reliable have been processed through the doctor blade method to realize a kind of field enhancement nanostructure, aiming to enhance the dielectric-barrier-discharge plasma actuation performance. It is found that the thrust enhancement rate could be approximately 72% at 13 kV and 8 kHz, compared to the controlled samples. In addition, a threshold phenomenon of the thrust enhancement effect was also found from the experiments, where the applied voltage and frequency lower than specific criteria could both lead to a decrease in the thrust generation and vice versa. It is suggested that the increase in the ionization frequency resulted from the field enhancement effect of the nanostructures is the leading mechanism for the extra thrust generation, which is inconsistent with the experimental examinations of the plasma characteristics and the plasma kinetic simulation. The results suggested that TiO2 nanoparticles could be used to improve the actuation performance in harsh environments with sound substrate compatibility.

Real-time parametric estimation of periodic wake-foil interactions using bioinspired pressure sensing and machine learning

Periodic wake-foil interactions occur in the collective swimming of bio-inspired robots. Wake interaction pattern estimation (and control) is crucial to thrust enhancement and propulsive efficiency optimization. In this paper, we study the wake interaction pattern estimation of two flapping foils in tandem configurations. The experiments are conducted at a Reynolds number of 1.41 × 104 in a water channel. A modified wake-foil phase parameter Φ, which unifies the influences of inter-foil distance L x , motion phase difference Δφ and wake convection velocity U v , is introduced to describe the wake interaction patterns parametrically. We use a differential pressure sensor on the downstream foil to capture wake interaction characteristics. Data sets at different tandem configurations are collected. The wake-foil phase Φ is used to label the pressure signals. A one-dimensional convolutional neural networks (1D-CNN) model is used to learn an end-to-end mapping between the raw pressure measurements and the wake-foil phase Φ. The trained 1D-CNN model shows accurate estimations (average error 3.5%) on random wake interaction patterns and is fast enough (within 40 ms). Then the trained 1D-CNN model is applied to online thrust enhancement control of a downstream foil swimming in a periodic wake. Synchronous force monitoring and flow visualization demonstrate the effectiveness of the 1D-CNN model. The limitations of the model are discussed. The proposed approach can be applied to the online estimation and control of wake interactions in the collective swimming and flying of biomimetic robots.

Performance Evaluation of LowThrust Rocket Nozzles of Various Geometries

Issues of viscous loss in rocket nozzle become increasingly more important as the thrust chamber is reduced in size. A properly designed nozzle is critical since small geometrical differences can result in dramatically modified performance. The present study analyzes the performance of conical converging-diverging nozzle for low-thrust rocket application. A total of five nozzles with different area ratio and divergence length were numerically tested; two optimum area ratio nozzles, one underexpanding nozzle and two overexpanding nozzles. The main aim is to analyze the flow phenomena of compressible gas flows within these nozzles and its relation to the rocket performance (i.e. thrust). The axisymmetric flow problems are numerically solved using a well-validated software with the Spalart-Allmaras turbulence model is employed to model the effect of turbulent on the flow. The results revealed technique of eliminating flow separation and obviously, knowledge of the point of separation is essential for performance enhancement. The elimination of flow separation inside the overexpanding nozzle by means of truncating it at a point of separation increases the thrust produced by 18% for a relatively low combustion pressure. It is anticipated that the thrust enhancement would be greater for a higher nozzle pressure ratio (NPR, i.e. the ratio of combustion chamber total pressure and atmospheric static pressure). With the demonstrated performance enhancement, this work serves as a driver for further nozzle enhancement using this technique.

Thrust and efficiency enhancement scheme of the fin propulsion of the biomimetic Autonomous Underwater Vehicle model in low-speed flow regime

Efficient low-speed Autonomous Underwater Vehicles (AUV) could adopt a propulsion mechanism with a biomimetic approach of caudal fin propulsion. The developments of the biomimetic AUV have very little attention to the systematic enhancement scheme of the fin performance. Therefore, many unclear relations of the parameters in thrust generation and efficiency of the various types of biomimetic fins. The present study proposes a systematic enhancement scheme of the static and dynamic performances of the biomimetic fins in a low-speed regime. This scheme involves rigid, cupping, and flexible single-joint fins of the acceleration-reaction fin mechanism and a high aspect ratio lunate shape two-joint fin of the lift-based fin mechanism. Average net-force and Thrust-to-Power Ratio evaluated the static performance, while the estimated cruising speed characterized the dynamic performance. The present study shows that the flexible single-joint fin improved the maximum values of the rigid fin performance by three times in average net-force, five times in thrust-to-power ratio, and two and a half times in estimated cruising speed. The two-joint fin enhanced the static and dynamic performances of the flexible fin by three times in average net-force, four times in thrust-to-power ratio, and one and a half times in estimated cruising speed. The present study suggests that flexibility has a role as a thrust vectoring factor. Furthermore, the lift-based mechanism in the two-joint fin provides effective and efficient thrust generation. In the present study, the two-joint fin was the effective and efficient fin propulsion mechanism in a low-speed regime.

Efficient thrust enhancement by modified pitching motion

Thrust and/or efficiency of a pitching foil (mimicking a tail of swimming fish) can be enhanced by tweaking the pitching waveform. The literature, however, show that non-sinusoidal pitching waveforms can enhance either thrust or efficiency but not both simultaneously. With the knowledge and inspiration from nature, we devised and implemented a novel asymmetrical sinusoidal pitching motion that is a combination of two sinusoidal motions having periods T1 and T2 for the forward and retract strokes, respectively. The motion is represented by period ratio $\mathrm{\mathbb{T}} = {T_1}/T$ , where T = (T1 + T2)/2, with $\mathrm{\mathbb{T}} > 1.00$ giving the forward strokes (from equilibrium to extreme position) slower than the retract strokes (from extreme to equilibrium position) and vice versa. The novel pitching motion enhances both thrust and efficiency for $\mathrm{\mathbb{T}} > 1.00$ . The enhancement results from the resonance between the shear-layer roll up and the increased speed of the foil. Four swimming regimes, namely normal swimming, undesirable, floating and ideal are discussed, based on instantaneous thrust and power. The results from the novel pitching motion display similarities with those from fish locomotion (e.g. fast start, steady swimming and braking). The $\mathrm{\mathbb{T}} > 1.00$ motion in the faster stroke has the same characteristics and results as the fast start of prey to escape from a predator while $\mathrm{\mathbb{T}} < 1.00$ imitates braking locomotion. While $\mathrm{\mathbb{T}} < 1.00$ enhances the wake deflection at high amplitude-based Strouhal numbers (StA = fA/U∞, where f and A are the frequency and peak-to-peak amplitude of the pitching, respectively, and U∞ is the freestream velocity), $\mathrm{\mathbb{T}} > 1.00$ improves the wake symmetry, suppressing the wake deflection. The wake characteristics including wake width, jet velocity and vortex structures are presented and connected with $S{t_d}( = fd/{U_\infty })$ , ${A^{\ast}}( = A/d)$ and $\mathrm{\mathbb{T}}$ , where d is the maximum thickness of the foil.

Double-Ducted Fan as an Effective Lip Separation Control Concept for Vertical-Takeoff-and-Landing Vehicles

This paper describes a novel inlet flow conditioning concept that significantly improves ducted fans’ performance and controllability. High angle-of-attack operation of ducted fans is very common in vertical-takeoff-and-landing systems. The new concept named double-ducted fan (DDF) uses a secondary shroud to control inlet lip-separation-related momentum deficit at the inlet of the fan rotor during edgewise flight. The DDF is helpful in a wide edgewise flight velocity range, and its corrective aerodynamic effect becomes more pronounced with increasing flight velocity. A conventional baseline duct operating at 90 deg angle of attack is compared to other novel double-ducted fan designs via three-dimensional, viscous, and turbulent flow computations. A custom actuator-disk model replaces the zonal computation of the complex and three-dimensional rotor flowfield in the rotating frame of reference. Both hover and edgewise flight conditions are considered around the ducted fan unit and inside the ducts. Significant improvements from several novel ducted fan designs are in the areas of vertical thrust enhancement, nose-up pitching moment reduction, and recovery of fan through-flow mass flow rate in a wide horizontal flight range. A variable DDF design, a partial DDF design, and a fan-in-wing implementation of the DDF are introduced.

Propulsive performance and vortex wakes of multiple tandem foils pitching in-line

Numerical studies are presented on the propulsive performance and vortex dynamics of multiple hydrofoils pitching in an in-line configuration. The study is motivated by the quest to understand the hydrodynamics of multiple fin–fin interactions in fish swimming. Using the flow conditions (Strouhal and Reynolds numbers) obtained from a solitary pitching foil of zero net thrust, the effect of phase differences between neighboring foils on the hydrodynamic performance is examined both in position-fixed two- and three-foil systems at Reynolds number Re=500. It is found that the three-foil system achieves a thrust enhancement up to 118% and an efficiency enhancement up to 115% compared to the two-foil system. Correspondingly, the leading-edge vortex (LEV) and the trailing-edge vortex (TEV) of the hindmost foil combine to form a ‘2P’ wake structure behind the three-foil system with the optimal phase differences instead of a ‘2S’ wake, a coherent wake pattern observed behind the optimal two-foil system. The finding suggests that a position-fixed three-foil system can generate a ‘2P’ wake to achieve the maximum thrust production and propulsive efficiency simultaneously by deliberately choosing the undulatory phase for each foil. When increasing Reynolds number to 1000, though the maximum thrust and propulsive efficiency are not achieved simultaneously, the most efficient case still produces more thrust than most of the other cases. Besides, the study on the effects of three-dimensionality shows that when the foils have a larger aspect ratio, the three-foil system has a better hydrodynamic performance, and it follows a similar trend as the two-dimensional (2D) foil system. This work aids in the future design of high-performance underwater vehicles with multiple controlled propulsion elements.

Geometric-control formulation and averaging analysis of the unsteady aerodynamics of a wing with oscillatory controls

Differential-geometric-control theory represents a mathematically elegant combination of differential geometry and control theory. Practically, it allows exploitation of nonlinear interactions between various inputs for the generation of forces in non-intuitive directions. Since its early developments in the 1970s, the geometric-control theory has not been duly exploited in the area of fluid mechanics. In this paper, we show the potential of geometric-control theory in the analysis of fluid flows, exemplifying it as a heuristic analysis tool for discovery of symmetry-breaking and unconventional force-generation mechanisms. In particular, we formulate the wing unsteady aerodynamics problem in a geometric-control framework. To achieve this goal, we develop a reduced-order model for the unsteady flow over a pitching–plunging wing that is (i) rich enough to capture the main physical aspects (e.g. nonlinearity of the flow dynamics at large angles of attack and high frequencies) and (ii) efficient and compact enough to be amenable to the analytic tools of geometric nonlinear control theory. We then combine tools from geometric-control theory and averaging to analyse the developed reduced-order dynamical model, which reveals regimes for lift and thrust enhancement mechanisms. The unsteady Reynolds-averaged Navier–Stokes equations are simulated to validate the theoretical findings and scrutinize the underlying physics behind these enhancement mechanisms.

Characterization of DBD plasma actuator with ZnO nanowire arrays

Researches in the plasma actuation are increasingly scrutinizing the methodology to enhance the thrust density for the application in the aerodynamic flow control. In this paper, a new method has been proposed and experimentally evaluated. This method is based on the deposition of nanoscaled structures on the electrode surface and the tuning of the applied voltages and frequency. It is found that the thrust enhancement rate resulted from the incorporation of the nanostructures could be approximately 78%, relative to the controlled group, under 14 kV and 7 kHz. However, a threshold effect has been founded across all of the tested samples, where lower applied voltage and frequency could lead to the decrease in the thrust generation. Capacitor charging effects are basically not sensitive to the introduction of the nanostructures in electrical characteristic. Other experimental features and electric field simulation results also indicate the effectiveness of introducing nanoscaled structures into DBD plasma actuators, thus providing a new way to improve mechanical performance.

Propulsion enhancement of flexible plunging foils: Comparing linear theory predictions with high-fidelity CFD results

The fluid–structure interaction of a flexible plunging hydrofoil immersed in a current is solved numerically to analyze its propulsion enhancement due to flexibility at Reynolds number 10000. After validating with available experimental data, the code is used to assess analytical predictions from a linear theory. We consider large stiffness ratios, with high thrust enhancement by flexibility, and small mass ratios appropriate for underwater propulsion. The maximum thrust enhancement is observed at the first natural frequency, accurately predicted by the linear theory algebraically. The magnitude of the maximum thrust is over-predicted by the theory as the flapping amplitude increases. For large Strouhal numbers the flow becomes aperiodic, which for large enough amplitudes happens at frequencies below the natural frequency. But even at these Strouhal numbers, the linear theory predicts quite well the frequency of maximum thrust enhancement and optimal propulsive efficiency. We conclude that the linear theory constitutes a reliable and useful guide for the design of underwater flexible flapping-foil thrusters, and we provide a practical chart to easily select the optimal flapping frequency as a function of the actuation point, the stiffness and the mass ratios of the hydrofoil.

Neutral atom density measurements of xenon plasma inside a μ10 microwave ion thruster using two-photon laser-induced fluorescence spectroscopy

This paper reports measurements of the xenon ground state and excited state densities inside a μ10 microwave ion thruster. This thruster exhibits a 40% thrust enhancement upon changing from the waveguide to the discharge chamber propellant injection mode. In the present work, the associated mechanism was quantitatively evaluated using two-photon laser induced fluorescence (TALIF) spectroscopy to monitor the thruster waveguide. The 834.7 nm emission from excited state xenon was investigated with a 224.3 nm dye laser to excite the Xe I 5p61 S0 6pʹ [3/2]2 state, compared with the emission without the laser. The resulting data confirm that the neutral density exhibits a linear relationship with the propellant flow rate in the cold gas and ionized state, while the ion acceleration decreases the neutral density by the same order of magnitude as the propellant utilization efficiency is changed. As the propellant flow rate increases, the collisions of neutrals that generate excited states occur in the waveguide and, when this process plateaus, the ground state emission suddenly increases. Propellant injection from the discharge chamber is evidently effective at suppressing collisions with electrons in the waveguide that generate excited states and that potentially interfere with microwave propagation.

A survey on the conceptual design of hypersonic aircraft powered by RBCC engine

Rocket-based combined-cycle (RBCC) powered vehicles have been widely recognized as the most promising aircraft solution that could dramatically reduce the cost of space transportation. Researchers and scientists worldwide have conducted considerable overall design researches to cope with the challenges in RBCC development including mode transition, thermal protection and thrust enhancement. According to the way to orbit and the configuration characteristics, the hypersonic aircraft powered by RBCC engine are classified as four categories: single-stage-to-orbit (SSTO) two-dimensional configuration, SSTO axisymmetric configuration, two-stage-to-orbit (TSTO) two-dimensional configuration, and TSTO axisymmetric configuration. This paper systematically presents the development of the conceptual design of RBCC-powered vehicles. Both the structural and operating key parameters like the weight distribution, the RBCC propulsion performance and take-off mode, et al. are introduced in detail. On this basis, a comparative analysis of the advantages and disadvantages of the orbit model, the configuration selection and takeoff modes are conducted. In addition, the application prospect and technology development direction for hypersonic aircraft are also discussed. At the same time, the lessons that can be drew from previous hypersonic vehicle concept design are explored.

Analytical results for the propulsion performance of a flexible foil with prescribed pitching and heaving motions and passive small deflection

Abstract

Effects of tunable stiffness on the hydrodynamics and flow features of a passive pitching panel

Three-dimensional numerical simulations are carried out to study the hydrodynamic performance and flow features of a bio-inspired underwater propulsor. The propulsor is constituted by a passive pitching panel. The leading edge of the panel is prescribed under a periodic heaving motion while the panel pitches passively due to the employing of a stiffness-lumped torsional spring at the leading edge. Effects of the torsional spring stiffness have been put emphases on. A real-time tunable stiffness strategy is presented and employed in the study. We first study the passive pitching effects on the hydrodynamics and flow features of the panel using a series of constant stiffness and then we study the tunable stiffness effects using cosinusoidal curve based waveforms, in which the effects of phase difference (φ) between the stiffness profile and the oscillation motion and as well as the effects of stiffness fluctuation amplitude (Gk) are investigated, respectively. The stiffness profile beneficial for propulsion efficiency is further applied to cases with different oscillation amplitudes. A high-fidelity immersed boundary method based direct numerical simulation (DNS) solver is employed to acquire the fluid dynamics and to simulate the flow. The panel passive pitching motion is solved by coupling the DNS flow solver and the Euler rigid body dynamic equation. Results show that for the constant stiffness cases, the panel generates sinusoidal-like pitching motion, and in certain stiffness range, flexibility could benefit efficiency while holding some extent of stiffness could enhance the thrust. For the tunable stiffness cases, it is found that both the mean thrust and propulsive efficiency improved when the stiffness change is in-phase with the heaving motion (φ=0°). The largest mean thrust is found at φ=120°. The wake profile shows that in the constant stiffness cases and φ=120° case, the panel in each cycle generates a pair of elongated and twisted vortex tubes, the vortex tubes in each pair interconnected with each other and induces unprofitable interactions. While in the φ=0° case the panel generates a pair of round and closed vortex loops in each cycle and the vortex loops separated directly after they have been detached from the panel and thus avoided the unprofitable vortex interactions. The stiffness fluctuation amplitude (Gk) effects study (all employing the in-phase stiffness profile) shows that all the three tested cases (Gk=0.25G0,0.5G0,0.75G0) acquired thrust and efficiency enhancement while the Gk=0.5G0 case acquired the largest efficiency benefit and the Gk=0.75G0 case had the largest thrust. Wake profiles show entire vortex loops may not be formed when Gk is small while larger Gk may affect the arrangement of the vortex loops thus may generate unprofitable vortex interactions. The results of cases with motions with variable oscillating amplitudes (A∗) show employing the real-time altering stiffness profile (φ=0°,Gk=0.5G0) improves the propulsion performance in a certain range of A∗ (0.4≤A∗≤0.8). Results from this paper demonstrated the potential of using real-time tunable stiffness in the design of passive pitching propulsors of underwater vehicles that pursue higher performance.

Brownian fluctuations and hydrodynamics of a microhelix near a solid wall

We combine two-photon lithography and optical tweezers to investigate the Brownian fluctuations and propeller characteristics of a microfabricated helix. From the analysis of mean squared displacements and time correlation functions we recover the components of the full mobility tensor. We find that Brownian motion displays correlations between angular and translational fluctuations from which we can directly measure the hydrodynamic coupling coefficient that is responsible for thrust generation. By varying the distance of the microhelices from a no-slip boundary we can systematically measure the effects of a nearby wall on the resistance matrix. Our results indicate that a rotated helix moves faster when a nearby no-slip boundary is present, providing a quantitative insight on thrust enhancement in confined geometries for both synthetic and biological microswimmers.

Effects of Heaving Motion on the Aerodynamic Performance of a Double-Element Wing in Ground Effect

The broad implication of the paper is to elucidate the significance of the dynamic heaving motion in the aerodynamic performance of multi-element wings, currently considered as a promising aspect for the improvement of the aerodynamic correlation between CFD, wind tunnel and track testing in race car applications. The relationship between the varying aerodynamic forces, the vortex shedding, and the unsteady pressure field of a heaving double-element wing is investigated for a range of mean ride heights, frequencies, and amplitudes, using a two-dimensional (2D) unsteady Reynolds-averaged Navier-Stokes (URANS) approach and an overset mesh method for modelling the moving wing. The analysis of the results shows that at high frequencies, i.e., k ≥ 5:94 and amplitudes a/c ≥ 0:05 the interaction of the shear vorticity between the two elements results in the generation of cohering leading and trailing edge vortices on the flap, associated to the rapid variation of thrust and downforce enhancement. Both the occurrence and intensity of these vortices are dependent upon the frequency, amplitude, and mean ride height of the heaving wing. The addition of the flap significantly alters the frequency of the shed vortices in the wake and maintains the generation of downforce for longer time in ground proximity. The comparison with the static wing provides evidence that the dynamic motion of a race car wing can be beneficial in terms of performance, or detrimental in terms of aerodynamic correlation.

Technological advancements in Pulse Detonation Engine Technology in the recent past: A Characterized Report

Pulse Detonation Engine (PDE), is an emerging and promising propulsive technology all over the world in the past few decades. A pulse detonation engine (PDE) is a type of propulsion system that uses detonation waves to combust the fuel and oxidizer mixture. Theoretically, a PDE can be operate from subsonic to hypersonic flight speeds. Pulsed detonation engines offer many advantages over conventional air-breathing engines and are regarded as potential replacements for air-breathing and rocket propulsion systems, for platforms ranging from subsonic unmanned vehicles, long-range transportation, high-speed vehicles, space launchers to space vehicles. This article highlights the operating cycle of PDE, starting with the fuel-oxidizer mixture, combustion and Deflagration to detonation transition (DDT) followed by purging. PDE combustion process, a unique process, leads to consistent and repeatable detonation waves. This pulsed detonation combustion process causes rapid burning of the fuel-oxidizer mixture, which cannot be seen in any other combustion process as it is a thousand times faster than any other mode of combustion. PDE not only holds the capability of running effectively up to Mach 5 but it also changes the technicalities in space propulsion. The present paper is the extension of the previous study which is also a well characterized status report of PDE in different areas. The present study deals with the categorization of the design approach, computations & simulations, flow visualization, DDT & Thrust enhancement, PDRE’s, experimental detonation engines with some of the experience and research undertaken in Punjab Engineering College under the complete supervision and guidance of Prof. Tejinder Kumar Jindal followed by applications of PDE technology.

Sounding rocket SS-520 as a CubeSat launch vehicle

This paper investigates the launch capability of the SS-520 as a CubeSat launch vehicle. The SS-520 was developed by JAXA originally as a two-stage, spin-stabilized, solid-propellant sounding rocket. With less than 2.6 tons in total mass and 10 m in length, the SS-520-5 successfully launched a single 3U-sized CubeSat into orbit on February 3, 2018. The SS-520-5 obtained its capability as a CubeSat launch vehicle by installing a 3rd stage solid motor in addition to the RCS between the 1st and 2nd stages. However, its launch capability was limited due to its rocket system configuration. In order to pursue the SS-520's launch capability, two effective modifications from the SS-520-5 are proposed: thrust enhancement of the 1st stage motor and installation of an additional RCS between the 2nd and 3rd stages. The framework of launch capability analysis is established by a multi-objective genetic algorithm (MOGA), where its two objectives are selected as the altitudes of perigee and apogee. The analysis reveals that the two proposed modifications to the SS-520-5 work effectively but differently. The 10% increase of the 1st stage enhancement is particularly effective when the target altitude of perigee is low (e.g., 200 km), whereas the installment of the additional RCS with 30 kg increases accessibility to a much higher altitude of perigee, even to circular orbit reaching altitudes of 550 km for a 1U-sized CubeSat and 280 km for a 6U-sized CubeSat. The simultaneous application of both modifications would result in launch capability able to deliver a 10-kg payload. From a more general perspective, the results in this paper suggest that it is possible for a very small launch vehicle (VSLV) of the 3-ton class and 10 m in length to deliver a 10-kg-class payload into low Earth orbit.