Initial Angle Of Attack Research Articles

Research on stability for blended-wing-body aircraft

The primary goal of this research is to research the stability properties of a blended-wing-body (BWB) aircraft. This section examines the assessment and selection of aircraft design parameters, planform design, and reflex wing and conducts a complete aircraft stability analysis. A BWB aircraft conceptual design has been completed and the design. To attain static stability, it was examined and refined. The BWB aircraft's study was performed at three distinct values. The analytical findings were used to calculate the angle-of-attack (AOA) and the stall AOA. We determined the estimated initial departure angle of attack and departure region by assessing the results of the trials and a set of stability criteria.

Dynamics of the Cl + CH3CN reaction on an automatically-developed full-dimensional abinitio potential energy surface.

A full-dimensional analytical potential energy surface (PES) is developed for the Cl + CH3CN reaction following our previous work on the benchmark abinitio characterization of the stationary points. The spin-orbit-corrected PES is constructed using the Robosurfer program and a fifth-order permutationally invariant polynomial method for fitting the high-accuracy energy points determined by a ManyHF-based coupled-cluster/triple-zeta-quality composite method. Quasi-classical trajectory simulations are performed at six collision energies between 10 and 60kcal mol-1. Multiple low-probability product channels are found, including isomerization to isonitrile (CH3NC), but out of the eight possible channels, only the H-abstraction has significant reaction probability; thus, detailed dynamics studies are carried out only for this reaction. The cross sections and opacity functions show that the probability of the H-abstraction reaction increases with increasing collision energy (Ecoll). Scattering angle, initial attack angle, and product relative translational energy distributions indicate that the mechanism changes with the collision energy from indirect/rebound to direct stripping. The distribution of initial attack angles shows a clear preference for methyl group attack but with different angles at different Ecoll values. Post-reaction energy distributions show that the energy transfer is biased toward the products' relative translational energy instead of their internal energy. Rotational and vibrational energy have about the same amount of contribution to the internal energy in the case of both products (HCl and CH2CN), i.e., both of them are formed with high rotational excitations. HCl is produced mostly in the ground vibrational state, while a notable fraction of CH2CN is formed with vibrational excitation.

Investigating the effect of physical parameters of a flexible vortex generator on the flow field and heat transfer inside a microchannel

A method to increase the heat transfer inside a microchannel is to limit the boundary layer, which can be achieved by installing a vortex generator on the bottom wall of the microchannel. Due to the stationary state of a rigid vortex generator (RVG), the beam is considered as a fixed boundary. Besides, the interaction between fluid and solid can be utilized to improve the performance in the flexible state. In this study, the effect of the physical parameters of a flexible vortex generator (FVG), including height, Young’s modulus, and initial attack angle, on the flow field and heat transfer is investigated. It is noteworthy that although the physical parameters affect the flow field downstream generator by changing the VG structure, not all the studied cases can result in vortex formation. The findings demonstrate that, regardless of the physical parameters, the average Nusselt number of the bottom wall for the FVG state is always larger than that of the RVG. In particular, the friction factor of the FVG is lower than that of the RVG for the initial attack angle of 30°. The performance coefficient of the FVG is inversely related to Young’s modulus and directly related to the height ratio and initial attack angle. For instance, increasing Young’s modulus from 0.4 MPa to 40 MPa causes the performance coefficient to rise by around 1.3 times. By comparison, the performance coefficient increases by almost three times when the height ratio increases from 0.4 to 0.8. Overall, it can be deduced that FVGs significantly enhance heat transfer performance compared to RVGs, highlighting the importance of optimizing the physical parameters to achieve maximum efficiency.

Mitigation mechanism of torsional vortex-induced vibrations using aerodynamic countermeasures: Case study on a typical closed-box girder

In this paper, a torsional simplified vortex model (SVM) framework is deduced from the time-frequency characteristics of the aerodynamic forces and related vortex drift patterns obtained by numerical flow visualization. With the SVM, the mechanism of torsional vortex-induced vibrations (VIVs) in a typical closed-box bridge girder is investigated, and then the mechanism for the mitigation of these VIVs with aerodynamic countermeasures, such as spoilers on handrails or guide vanes near maintenance rails, is analysed. The results reveal that large-amplitude torsional VIVs occur in the bridge girder at an initial angle of attack (AOA) of + 3°. The spoilers can almost eliminate VIVs, whereas the guide vanes can moderately suppress them. The contributions of distributed aerodynamic moment to the global vortex-excited moment (VEM) on the upper surface of both the original and guide vane girders are much larger than those on the lower surface, implying that the aerodynamic behaviour over the upper surface is predominant in exciting and sustaining VIVs. The contributions of distributed aerodynamic moment to the global VEM on the improved girder with spoilers are much smaller than those on the original girder, particularly on the upper surface, which cannot trigger VIVs. Thus, VIVs disappear when the spoilers are installed on handrails. Subsequently, the flow fields during VIVs are obtained by numerical flow visualization. For both the original and guide vane girders, the torsional VIVs are mainly excited by the separated vortices forming at the windward barriers over the upper surface, while the separated vortices over the lower surface also make slight contribution to VIVs. After the guide vanes are installed near the maintenance rails, the scales of vortices over both the upper and lower surfaces are reduced, resulting in a weaker impact on the girder, which is fundamentally responsible for the mitigation effect of the guide vanes.

Experimental study on the water entry of a vehicle with a single canard wing at an initial angle of attack

The use of flow control techniques is important to enhance vehicle motion stability during water entry. This paper introduces a method that applies a canard wing to the water entry problem, and the vertical water-entry process of a vehicle with a single canard wing at an initial angle of attack was experimentally studied. The cavity evolution and vehicle kinematics during water entry at various impact velocities and initial angles of attack were investigated. The results indicate that the fore-end cavity and the attached cavity on the wing are features of a vehicle with a canard wing during water entry. Unlike a wingless vehicle, the canard-wing configuration provides a restoring moment that corrects the deflection of the trajectory and attitude. As the impact velocity increased, the vehicle trajectory gradually corrected to a vertical straight-line trajectory before deflecting in the direction opposite to the side without a wing. As the initial angle of attack increased, the vehicle trajectory gradually shifted towards the side with the wing; however, the attitude remained stable without continuous deflection. The canard wing prevents a continuous change in attitude deflection caused by the initial angle of attack.

Fast predicting the trajectory of chip-like particles by integrating a discrete element method model with a computational fluid dynamics-based aerodynamic database

The accumulation of ice within aircraft engines poses a significant safety concern, necessitating effective and accessible methods to predict ice particle shedding trajectories. This study develops a novel method by integrating the discrete element method with a computational fluid dynamics (CFD)-based aerodynamic database, aiming to accurately predict the trajectories of chip-like ice particles under various conditions. The accuracy of the CFD-based aerodynamic database is validated through a quantitative comparison with experimental data, and the predicted trajectories align well with the experimental trajectories under varied conditions following a database-independence analysis. The results indicate that aerodynamic coefficients are independent of both the relative velocity and the scaling factor (k) for chip-like particles. Moreover, the initial angle of attack significantly influences the translational and rotational dynamics of chip-like particles. Furthermore, the chip-like ice particles released closer to the engine inlet exhibit a more uniform distribution of landing points, whereas those released at longer distances from the engine inlet tend to converge toward the central area of the engine. The methodology developed in this paper is expected to be a promising tool for fast predicting the trajectories of chip-like particles, thereby enhancing engine protection against ice impacts and improving overall operational safety.

Dynamic analysis of a skeet-inspired vehicle to achieve a spiral scanning detection motion

A short cylindrical vehicle (the ratio of length to diameter is less than 2) equipped with an outer/inner detector is developed, which is inspired by the Tennis racket theorem and Olympic skeet shooting sports to achieve a regular scanning spiral on the ground. The sensitivity of the asymmetric mass distribution of the skeet-inspired vehicle (SIV) to the spatial position of the inertial principal axis is evaluated. Subsequently, a dynamics model with six degrees of freedom for the SIV at a large initial angle of attack (≈60–90°) is established. The numerical results of solving the dynamic differential equations indicate that the special initial conditions—namely, high initial flying velocity and rotational speed—are prerequisites for achieving the regular scanning spiral. Additionally, the analysis demonstrates that asymmetric mass distribution, rather than asymmetric aerodynamics, serves as the key factor in achieving the regular scanning spiral in the present skeet-inspired vehicle. Our new strategy, using the principal axes as the initial rotation axis, offers better scanning performance (such as a larger detection area, faster scan frequency, and more stable scanning motion) compared to the other platforms (e.g., rotating decelerators with wings or parachutes) that rely on asymmetrical aerodynamics. The analyses can provide guidance for the structural design of various types of spiral scanning vehicles.

Automated potential energy surface development and comprehensive dynamics for the F + CH3NH2 reaction.

This work is an extensive investigation of the F + CH3NH2 reaction dynamics using a newly-developed potential energy surface (PES). The full-dimensional spin-orbit (SO) corrected (MRCI+Q/aug-cc-pwCVDZ) PES is developed by the Robosurfer program package and the ManyHF method is used in order to fix the Hartree-Fock (HF) convergence issues in the entrance channel. On the surface, retrieved by the fitting of the iteratively extended set of the ManyHF-CCSD(T)-F12a/triple-zeta-quality and SO-corrected energy points, quasi-classical trajectory (QCT) simulations are run. By analyzing the opacity functions and integral cross sections (ICSs) of six reaction channels, the dynamics of the two most reactive hydrogen-abstraction reactions resulting in HF + CH2NH2/CH3NH products are selected for a thorough examination. Despite the statistically and thermodynamically expected results, the kinetically preferred amino hydrogen-abstraction is the dominant mechanism at low collision energies. The initial attack angle and scattering angle distributions are investigated as well. The post-reaction energy distributions show that the collision energy mostly converts into the translational energy of the products, while the reaction energy excites the vibration of the products. The computed vibrationally resolved rotational distributions and vibrational state distributions of the HF product are compared to experimental data, and the theory and experiment are found to be in good agreement.

Vibrational mode-specificity in the dynamics of the OH- + CH3I multi-channel reaction.

We report a comprehensive characterization of the vibrational mode-specific dynamics of the OH- + CH3I reaction. Quasi-classical trajectory simulations are performed at four different collision energies on our previously-developed full-dimensional high-level abinitio potential energy surface in order to examine the impact of four different normal-mode excitations in the reactants. Considering the 11 possible pathways of OH- + CH3I, pronounced mode-specificity is observed in reactivity: In general, the excitations of the OH- stretching and CH stretching exert the greatest influence on the channels. For the SN2 and proton-abstraction products, the reactant initial attack angle and the product scattering angle distributions do not show major mode-specific features, except for SN2 at higher collision energies, where forward scattering is promoted by the CI stretching and CH stretching excitations. The post-reaction energy flow is also examined for SN2 and proton abstraction, and it is unveiled that the excess vibrational excitation energies rather transfer into the product vibrational energy because the translational and rotational energy distributions of the products do not represent significant mode-specificity. Moreover, in the course of proton abstraction, the surplus vibrational energy in the OH- reactant mostly remains in the H2O product owing to the prevailing dominance of the direct stripping mechanism.

Spatio-temporal distribution of aerodynamic forces and their associated vortex drift patterns around a closed-box girder during torsional vortex-induced vibration

Torsional vortex-induced vibrations (VIVs) pose potential risks to prototype bridges with increasing spans and lower damping levels. However, the underlying mechanism remains unclear. Wind tunnel tests revealed that torsional VIVs occurred at an initial attack angle of + 3°. To unravel the VIV mechanism throughout the lock-in range, encompassing the ascent stage, amplitude extremum, and descent stage, the spatio-temporal distribution of aerodynamic forces around the bridge girder was analyzed. The results demonstrated the presence of traveling pressure waves with approximately 2.5 wavelengths and three uniformly distributed separated vortices over the upper side throughout the lock-in range. The primary source of these travelling pressure waves stemmed from the vortex drift patterns, with the aerodynamic wave travelling velocity equating the vortex drift velocity. The formation of separated vortices, known as the “double-vortex model”, occurred at the windward barrier on the upper side and windward maintenance rail on the lower side. These vortices directly imposed travelling pressure waves on the girder, thereby inducing torsional VIVs. Among them, the former vortices contributed more to the VIVs than the latter. Therefore, the formation of separated vortices and their related aerodynamic waves in the windward edge with the 2nd SVM/AWM modes predominantly governed the occurrence of torsional VIVs. Furthermore, both the ratio of the wave travelling time to the vibration period and the mean value of the wave travelling velocity ratio exhibited an inverse relationship with the VIV responses. However, the actions exerted by the vortex drift patterns were proportional to the VIV responses on both the upper and lower sides. Therefore, there existed evolutionary characteristics of aerodynamic waves and their related vortex drift patterns throughout the lock-in range, which was responsible for the “lock-in” phenomena.

ManyHF-based full-dimensional potential energy surface development and quasi-classical dynamics for the Cl + CH3NH2 reaction.

A full-dimensional spin-orbit (SO)-corrected potential energy surface (PES) is developed for the Cl + CH3NH2 multi-channel system. Using the new PES, a comprehensive reaction dynamics investigation is performed for the most reactive hydrogen-abstraction reactions forming HCl + CH2NH2/CH3NH. Hartree-Fock (HF) convergence problems in the reactant region are handled by the ManyHF method, which finds the lowest-energy HF solution considering several different initial guess orbitals. The PES development is carried out with the Robosurfer program package, which iteratively improves the surface. Energy points are computed at the ManyHF-UCCSD(T)-F12a/cc-pVDZ-F12 level of theory combined with basis set (ManyHF-RMP2-F12/cc-pVTZ-F12 - ManyHF-RMP2-F12/cc-pVDZ-F12) and SO (MRCI+Q/aug-cc-pwCVDZ) corrections. Quasi-classical trajectory simulations show that the CH3-side hydrogen abstraction occurs more frequently in contrast to the NH2-side reaction. In both cases, the integral cross sections decrease with increasing collision energy (Ecoll). A reaction mechanism shifting from indirect to direct stripping can be observed from the opacity functions, scattering angle, and translation energy distributions as Ecoll increases. Initial attack angle distributions reveal that chlorine prefers to abstract hydrogen from the approached functional group. The collision-energy dependence of the product energy distributions shows that the initial translational energy mainly transfers to product recoil. The HCl vibrational and rotational energy values are comparable and nearly independent of collision energy, while the CH2NH2 and CH3NH co-products' vibrational energy values are higher than the rotational energy values with more significant Ecoll dependence. The HCl(v = 0) rotational distributions are compared with experiment, setting the direction for future investigations.

Vibrational Mode-Specific Dynamics of the OH + C2H6 Reaction.

We investigate the effects of the initial vibrational excitations on the dynamics of the OH + C2H6 → H2O + C2H5 reaction using the quasi-classical trajectory method and a full-dimensional analytical ab initio potential energy surface. Excitation of the initial CH, CC, and OH stretching modes enhances, slightly inhibits, and does not affect the reactivity, respectively. Translational energy activates the early-barrier title reaction more efficiently than OH and CC stretching excitations, in accord with the Polanyi rules whereas CH stretching modes have similar or higher efficacy than translation, showing that these rules are not always valid in polyatomic processes. Scattering angle, initial attack angle, and product translational energy distributions show the dominance of direct stripping with increasing collision energy, side-on OH and isotropic C2H6 attack preferences, and substantial reactant-product translational energy transfer without any significant mode specificity. The reactant vibrational excitation energy of OH and C2H6 flows into the H2O and C2H5 product vibrations, respectively, whereas product rotations are not affected. The computed mode-specific H2O vibrational distributions show that initial OH excitation appears in the asymmetric stretching vibration of the H2O product and allow comparison with experiments.

Numerical research of high-speed oblique water-entry of projectile based on rigid body and fluid-structure interaction model

When a projectile enters the water at high speed, the projectile can suffer a huge impact of water. If a deformation occurs in the structure of the projectile during water-entry, the numerical method based on rigid body model will be limited, while the accuracy and precision of the results can be affected. The two numerical methods of the rigid body and fluid-structure interaction (FSI) model have been built to get the results of the oblique water-entry of the projectile in this paper. Moreover, the numerical results for the given projectile under the same water-entry conditions (initial angle of incidence of θ = 15°, initial angle of attack of α = 5°, initial speed of V = 200m/s ) have been contrasted. The results show that if a small deformation occurs in the body of the projectile during the water-entry, the numerical results of the FSI and the rigid body are different. Further, the small deformation within the limit of flexibility can change the motion attitude and the trajectory of projectile during the water-entry, meanwhile the change can cause the bending of the ballistic and the super-cavity. For the projectile with the structural response, the change in the distribution of the stress concentration area can affect the drag force suffered by projectile.

Dynamics of the Cl- + CH3I reaction on a high-level abinitio analytical potential energy surface.

We have developed a full-dimensional analytical abinitio potential energy surface (PES) for the Cl- + CH3I reaction using the Robosurfer program system. The energy points have been computed using a robust composite method defined as CCSD-F12b + BCCD(T) - BCCD with the aug-cc-pVTZ(-PP) basis set and have been fitted by the permutationally invariant polynomial approach. Quasi-classical trajectory simulations on the new PES reveal that two product channels are open in the collision energy (Ecoll) range of 1-80 kcal/mol, i.e., SN2 leading to I- + CH3Cl and iodine abstraction (above ∼45 kcal/mol) resulting in ICl- + CH3. Scattering angle, initial attack angle, product translational energy, and product internal energy distributions show that the SN2 reaction is indirect at low Ecoll and becomes direct-rebound-back-side (CH3-side) attack-type, as Ecoll increases. Iodine abstraction mainly proceeds with direct stripping mechanism with side-on/back-side attack preference. Comparison with crossed-beam experiments and previous direct dynamics simulations shows quantitative or qualitative agreement and also highlights possible theoretical and/or experimental issues motivating further research.

Three-dimensional trajectory prediction and analysis of elliptical projectile

This article establishes a three-dimensional trajectory model for an elliptical projectile into semi-infinite target based on rigid dynamics and the idea of isolation between the projectile and target. The reliability of the proposed model is verified through a series of normal and oblique penetrations, and the predicted results agree well with the experimental and simulation data. In addition, the effects of the structural parameters and striking conditions of the elliptical projectile on the trajectory stability are discussed. Compared with a circular projectile with a particular initial pitch or yaw angle, the anti-deflection ability of the elliptical projectile on its minor-axis side is increased, whereas that on the major-axis side is decreased. The introduction of a roll angle for the elliptical projectile results in two lateral resistances, causing a rotational motion along its longitudinal axis. Compared with a circular projectile with a particular initial attack or sideslip angle, an elliptical projectile exhibit increased anti-deflection ability on its major-axis side, and reduced anti-deflection ability on its minor-axis side. This preliminary study on the ballistic behavior of non-circular projectiles provides guidance for the design and application of such projectiles.

Static Wind Reliability Analysis of Long-Span Highway Cable-Stayed Bridge in Service

Long-span cable-stayed bridge is a typical wind-sensitive structure because of its light weight and great flexibility. The reliability evaluation of the cable-stayed bridge under wind action becomes a key issue during bridge design and operation. In this paper, taking Xiangshan Harbor highway cable-stayed bridge in Ningbo City in China as the engineering background, ANSYS 15.0 is used to build a finite element model of this bridge to explore its aerostatic stability and influencing parameters, then the static wind reliability of this bridge is analyzed. Firstly, considering the structural nonlinearity and the nonlinearity of static wind load comprehensively, the critical wind speed of aerostatic instability of the Xiangshan Harbor cable-stayed bridge is calculated by the internal and external double iteration method. Then the influence of the initial wind attack angle, steel wire breakage rate of the stay cables, static three-component force coefficients, and cable broken position on the static wind stability of this bridge are discussed. Thus, the variation rule of the critical aerostatic instability wind speed is obtained, and the parameter that has the greatest impact on the static wind stability of the cable-stayed bridge in service is determined. Finally, considering the randomness of these key parameters, they are treated as random variables, Latin hypercube sampling (LHS) method is used to obtain samples of random variables to calculate aerostatic instability wind speed for a given sample by self-written calculation program, and on this basis, static wind reliability analysis is conducted by the checking point method, which provides strong support for the static wind risk evaluation of the existing long-span cable-stayed bridge.

Numerical investigation of the unsteady effect owing to oscillation on airfoil icing

Modeling the unsteadiness owing to body motion is essential for accurately simulating ice accretion on a moving object. For an oscillating airfoil, high-frequency oscillations have been assumed to occur in slow motion to apply a quasi-steady approach to numerical analysis. The method raised arbitrariness in the number of data exchanges and the initial angle of attack. Simultaneously, the oscillation owing to a change in the angle of attack was considered for each step. Subsequently, the quasi-unsteady approach was proposed, the results from which exhibited good agreement for a few ice shapes, unlike that of the extended quasi-steady approach. However, whether a quasi-unsteady approach is sufficiently accurate for simulating ice accretion on a two-dimensional oscillating airfoil under various conditions still remains unknown. This study analyzed the unsteady effect on collection efficiency and convective heat transfer using the quasi-unsteady approach. Furthermore, as the static case, this approach demonstrated that the roughness and laminar-turbulent transition model for the oscillating airfoil can improve the prediction of the ice shape. The results obtained from this approach using the improved model exhibited good agreement with previously reported experimental results.Fig. 11 compared predicted ice shape with different roughness height. Fig. 11(a) is Run 61 with a reduced frequency of 0.044 at an LWC = 1 g/m3, and Fig. 11(b) is Run 50 with a reduced frequency of 0.027 at an LWC =.55 g/m3 The dotted line indicates the experimental ice shape and the dashed line indicates the numerical results applied to the empirical roughness model. The solid line indicates ice shape with the roughness size when the direction and size of the ice horn closely match the experimental values. When an empirical roughness model is applied, the ice horns are usually concentrated near the leading edge. Roughness increases convective heat transfer and premature laminar turbulence in ice accretion. The convective heat transfer peaks near the leading edge with a high roughness value; therefore, the ice horn gathers near the leading edge. Low roughness delayed the formation of the ice horn due to the decreased heat transfer rate, which balances the latent heat of icing, thereby allowing the droplets to freeze before moving to the trailing edge. In Run 61, the ice shape was predicted accurately at 20 % of the empirical roughness and 40 % roughness height of Run 55. When the roughness height was reduced, such as in the case of Run 61 with 10 % empirical roughness, the primary horn reduced, whereas the secondary horns increased.

Fragility analysis of curtain walls based on wind-borne debris considering wind environment

Increasing attention has been attached to the risk assessment and fragility analysis of envelopes of high-rise buildings subjected to the impact of wind-borne debris in hurricanes or typhoons. A probabilistic model of wind-borne debris is proposed in the present paper for risk assessment and fragility analysis of high-building curtain walls based on the numerical solution of three-dimensional flight trajectories of debris and the computational fluid dynamics simulation of local wind environment in a residential area. The influence of sources of randomness in the generation of debris, such as generated location, size, and initial attack angle, as well as local wind environment, on the location of debris impacting on the building curtain wall and the impact damage effect, are considered in the proposed model. The evolution of the probability characteristics of debris is driven by its physical flying behavior in the local wind environment, and the failure probability of each piece of glass of building curtain walls impacted by debris can be determined. Furthermore, a numerical algorithm is given for the fragility analysis under different incoming wind speeds, which can be used to determine the vulnerability and the fragility curve. Finally, two numerical examples for application to residential areas are provided. Results show that the proposed model can provide evaluation and prediction for wind disaster risk and fragility of high-rise buildings in urban areas.

Numerical Simulation of Galloping Characteristics of Multi-Span Iced Eight-Bundle Conductors Tower Line System

The galloping condition of an iced eight-bundle conductor tower line system, under different parameters, is studied by using a finite element model of a multi-span iced eight-bundle conductor tower line system. The galloping frequency, amplitude, traces of multi-span iced eight-bundle conductors under different wind velocities, span lengths, and initial angles of wind attack are discussed. The different tower line connection methods are compared, based on existing research on the relationship between the aerodynamic characteristics of the conductor and galloping conditions. The results show that the galloping situation of a multi-span iced eight-bundle conductor tower line system varies greatly depending on the conditions, which has a significant impact on the tower line.

Load and motion behaviors of ogive-nosed projectile during high-speed water entry with angle of attack

Hazardous loads exist not only during the water impact but during the entire high-speed water entry process. This article systematically investigates the load behavior of an ogive-nosed projectile during the entire process from the impact to the full wetting by experimental and numerical methods. It is found that the hazardous loads during the entire water entry process mainly exist in the three stages of water impact, tail slap and beginning of wetting. The formation mechanisms of hazardous loads are revealed. The initial angle of attack (IAA) within 8° in absolute value has little influence on the axial load, with the maximum difference of 4 g. In contrast, the effect of the IAA on the radial load is significant in terms of the direction, the peak, the beginning time of wetting, and the magnitude after wetting. The peak radial load of the tail slap reaches 3.7 times the peak axial impact load at the IAA of −8°. When the IAA is large (±8°), serious deflection of the trajectory occurs, such as the water exit at +8° and the backward movement at −8°; the angle of attack eventually diverges; and the pitch angle change reaches over 200°. The results provide helpful guidance in effectively identifying all hazardous loads during the entire water entry process and clearly understanding the motion behavior under the action of the loads.