Hongbin LI, Jinling LI,*, Ch XIONG, Wei FAN, Lei ZHAO,Wenhu HAN

a School of Power and Energy, Northwestern Polytechnical University, Xi’an 710072, China

b Shaanxi Key Laboratory of Internal Aerodynamics in Aero-Engine, Xi’an 710072, China

c State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China

KEYWORDS Active control;Hot jet;Numerical simulation;Oblique detonation wave;Supersonic propulsion

Abstract The hot jet injection is utilized to actively control the oblique detonation wave, such as initiating and stabilizing an oblique detonation wave at a desired position that is shorter than the length of induction zone, and adjust the height of the oblique detonation wave at the exit of combustor when the oblique detonation wave engine is working on off-design flight conditions.The fifth order Weighted Essentially Non-Oscillatory (WENO) scheme and a two-step reversible reaction mechanism of the stoichiometric H2/Air are adopted in the simulations. With the help of hot jet injection,the transition from inert oblique shock wave to the oblique detonation wave immediately occurs near the position of hot jet injection, and consequently the length of combustor can be reduced. The angle of oblique detonation wave also decreases as the hot jet injection approaches the nose of wedge.Additionally,the height of the oblique detonation wave at the exit of combustor can be flexibly adjusted,and also depends on the injection position and the strength of the hot jet.If the velocity of the hot jet is too weak to directly trigger the overall oblique detonation wave at the position of injection, increasing the injection pressure will improve the strength of the hot jet and results in a successful transition.

1. Introduction

Compared with scramjet, supersonic propulsion devices based on detonation have attracted special attentions for the higher thermodynamic efficiency and higher heat release rate.1,2The Oblique Detonation Wave Engine (ODWE) is a kind of propulsion device based on the Oblique Detonation Wave(ODW), which is considered to be more applicable to the hypersonic air breathing flight.However, for the conventional wedge to initiate and stabilize an ODW in the combustor of ODWE, there still exists big challenges for ODWE operating at the optimum state during its flight conditions. One of the challenges of the conventional wedge is how to effectively initiate an ODW at a desired location and stabilize it over the entire flight time.

In general, the ODW structure is composed of a nonreactive induction region and the reactive detonation front. Teng et al.3analyzed the effect of inflow pressure,and Mach number on the induction structure and length. The investigation of Teng et al. also demonstrated two transition structures, i.e.,an abrupt transition from a multi-wave point connecting the oblique shock and the detonation surface and a smooth transition via a curved shock. These structures strongly depend on the inflow Mach number. Furthermore, the effect of Mach number on induction length is independent of pressure, but given the same Mach number, the induction length is found to be inversely proportional to pressure. Zhang et al.4carried out the numerical studies related to the ODW initiation in H2/Air mixtures at various equivalence ratios. The results shown that the dependence of induction length on fuel-air equivalence ratio follows a U-shaped curve with the minimum length around the ratio of 0.8. The induction length drastically increases below this critical equivalence ratio. In order to reduce the induction length, a dual-angle wedge structure was numerically studied by Bhattrai and Tang5The first section of the dual-angle is a large angle wedge which induces an overdriven ODW,and the second section following the former is a small angle wedge that relaxes the overdriven ODW to a Chapman-Jouguet (CJ) ODW by interacting with the expansion waves resulting from the deflection of wedge angle.Compared with the single-angle wedge structure, the induction length with the dual-angle wedge structure is shorter.Furthermore, it is possible to stabilize an ODW on a finite-length wedge shorter than the length of induction zone for large cone angles at high pressure according to the studies of Ref.6,7, i.e.the prompt ODW, but the formation of a prompt ODW at other condition is not reported.

As the most widely used structure to initiate and stabilize an ODW, another challenge of the wedge is how to adjust the incline angle8according to the real flight conditions. For a conventional ODWE geometry whose combustor is followed by an expansion nozzle, as presented in Ref.9,the issue is that the height of ODW at the exit of combustor is either too low to touch the upper wall surface at all, as shown in Fig. 1(a), or touches the upper wall surface upstream of the combustor exit,as shown in Fig. 1(b). The first condition results in low combustion efficiency,since a part of the fuel-air mixture spills into the nozzle without passing through the combusting ODW.And the second case of the combustor characteristics associated with ODW touching of the upper wall surface upstream of the combustor exit is also detrimental to the ODW performance, since it leads to a local extremely high temperature region, the friction losses due to reflected ODW at combustor upper wall surface,and wall-boundary layer separation due to the shock wave-boundary layer interaction. Therefore, a method which is able to flexibly adjust ODW at the offdesign flight conditions of ODWE is needed to be investigated.However, the conventional method based on changing the combustor geometry may largely increase the complexity of the ODWE configuration. Hence, it is necessary to develop an active control method to solve the problems of ODWE,especially for the problems occurred at the off-design flight conditions. In the active flow control field, the arc discharge plasma is often used to adjust the start point and the angle of shock wave. The dominant mechanism10of this adjustment is that a new plasma wedge forms near the discharge zone because of the thermal choking, and the chemical effects of plasma are not important.

Compared with the wedge structure, the hot jet is another method for detonation initiation and stabilization in the supersonic combustible mixtures. Han et al.11successfully initiated the ODW with a hot jet in a straight channel. Chen et al.12investigated the mechanism of detonation combustion in an expanding channel filled with supersonic combustible mixtures of a stoichiometric H2/Air. In their studies,11,12the hot jet is strong enough to initiate the detonation instead of the wedge,and the outflow of the hot jet is an equilibrium CJ state of a stoichiometric H2/O2mixture.In this paper,the hot jet,which is transversely injected to the main flow at the induction zone,is utilized to actively control the ODW in the combustor of ODWE, such as initiating the ODW at a desired position which is shorter than the length of the induction zone and adjusting the height of ODW at the exit of combustor at the off-design flight conditions. The strength of the hot jet is decreased to the equilibrium CJ state of the stoichiometric H2/Air mixture or even weaker than it.

2. Numerical methods and physical model

2.1. Numerical methods

Fig. 1 Schematic of ODW in the combustor at off-design flight conditions.

The unsteady two-dimensional Euler equations coupled with a two-step reversible reaction model of stoichiometric H2/Air13are used. Romick et al.14calculated the 1-D viscous detonations with supporting piston and detailed H2/air mechanism.It was shown that the effect of viscosity was weakened as the overdriven degree of detonation wave decreased. Hence, the results obtained by the Navier-Stokes equations were indistinguishable from the inviscid predictions for the moderately unstable detonation.Based on the numerical and experimental studies, Radulescu et al.15suggested that the consumption of most portions of gases caused by the turbulence mixing cannot be ignited by the shock compression in the irregular detonations. In regular detonation structure, the shock compression mechanism could ignite almost all the gases passing through the shock front. In highly unstable detonations, the unburned pockets of reacted and unreacted gases were consumed by turbulent mixing at their boundaries via vortices produced by RM and K-H instabilities.15Han et al.16confirmed the moderate effect of viscosity diffusion on the pulsation for global CJ detonations through detailed reaction mechanism. In the present simulations, the natural property of detonation is classified as the category of stable and weakly unstable detonation.Consequently,the role of viscosity in ODW structure should be subtle.Therefore,the viscous effects on ODW are also assumed to be negligible,and the governing equations are shown as below:

where the conserved variable vector U, the inviscid convective flux vectors E and F in the x and y directions,and the chemical reaction source term vector S are respectively given by

where ρ, u, v, p, and e represent the fluid density, velocities in the x and y directions, pressure and specific total energy,respectively. The specific total energy is given by

where q is the heat release of chemical reaction per unit mass,and γ is the specific heat ratio.The chemical reaction rates are given by the following expressions

where α is the progress variable of induction reaction, which decreases from unity;and β is the progress variable of exothermic reaction, which decreases from unity when α goes below zero. R and T are gas constant and temperature, and the parameters that utilized in the model, E1, E2, k1, k2and q,are the same as the study of Liu et al.7respectively, as shown in Table 1.

To numerically solve the governing equations,a fifth-order local characteristics based on Weighted Essentially Non-Oscillatory (WENO)17conservative finite difference scheme is employed to discretize the advection term. A third-order TVD Runge-Kutta method18is applied for temporal dis-cretization,and the Lax-Friedrichs splitting approach18is used to split the flux vectors.To accelerate the numerical simulation process,a parallel method based on Message Passing Interface(MPI) is used in the present work.

Table 1 Parameters of reaction model.

2.2. Physical model

A design9,19of ODWE is shown in Fig. 2. Considering the flight altitude of 30 km and the Mach number of 10, it is assumed that the hypersonic flow is firstly pre-compressed twice by weak oblique shock waves in the inlet diffuser. For simplicity,the fuel mixing process in the inlet is not considered,which means that the inflow of combustor is assumed to be well premixed. Then, the combustible inflow reflects on the two-dimensional wedge and generates an oblique shock wave.The oblique shock wave may trigger exothermic chemical reactions and subsequently induce an oblique detonation wave in the combustor.

Three typical ramp angles θ are assumed to be 12.5°, 10.0°and 7.5°. The static pressure P1, static temperature T1and Mach number Ma1behind the second attached oblique shock wave could be easily obtained based on the oblique shock wave theory respectively.The inflow Mach number Ma1,pressure P1and temperature T1of combustor are listed in Table 2.A series of deflection angles δ in the combustor are selected to investigate the behaviors of ODW at different cases with hot jet.However, the δ of Case 1 is less than CJ angle whose value is the critical angle to stabilize a CJ oblique detonation wave based on R-H theory.20In such a case, an oblique CJ detonation can exist on the wedge with an expansion fan downstream of the reaction zone matching the flow angle with that of the wall.21

Fig. 2 Configuration of ODWE.

Table 2 Inflow parameters of combustor.

The computational domain in the combustor and a simple structure of ODW are shown in Fig. 3. The computational domain is a rectangle above the wedge surface, i.e. the rectangle with dashed line shown in Fig. 2, and the axes x and y are parallel and vertical to the wedge surface respectively.

The inlet boundary condition is fixed at the prespecified values of a H2/Air mixture with stoichiometric molar ratio, such as the P1,T1and Ma1shown in Table 2.Slip reflection boundary condition is used at the wedge surface. Several additional grids are added upstream of the wedge surface to avoid any numerical reflection from the left boundary, the flow properties at the exit plane are extrapolated from the interior. The width of the hot jet which is vertically injected from the wedge surface is 4 mm,11as shown in Fig. 3. The hot jet is set to the equilibrium CJ state of the stoichiometric H2/Air mixture whose initial pressure and temperature are the same with the cases of combustor inflow shown in Table 2, the parameters of equilibrium CJ state are calculated by the CEA software.22

2.3. Grid independence test

All the calculations presented in this study are performed using a uniform mesh in both directions, six different grid sizes,Δx1=0.075 mm, Δx2=0.06 mm, Δx3=0.05 mm,Δx4=0.04 mm, Δx5=0.025 mm and Δx6=0.015 mm are selected to choose the suitable grid size.The inflow parameters are the same with Case 4, as shown in Table 2. To check the convergence of numerical scheme, the Richardson Extrapolation method23,24is used to estimate the order of accuracy.The lengths of induction zone along the streamline y=0.22Linobtained with different grid resolutions are investigated, as thein shown in Fig. 4. The convergence condition is oscillatory,25so the power law iterative method26is utilized to estimate the convergence rate p and the exact value. The discretization error ε and grid resolution Δx are plotted on a log-log scale in Fig. 4, and the line with square points indicates the log value of ABS(ε) (absolute value of the discretization error).The convergence rate p=3.4 is below the design order because the weighting process reduces the accuracy of reconstruction where shock occurs, otherwise,strong discontinuity may induce computational instability.

Fig. 3 Schematic of computational domain.

For the compromise of the computational tasks and accuracy,the grid solution Δx3is selected to conduct the following simulations.To further investigate the convergence of the simulation, we also compare the variations of pressure and reaction process along the streamline of y=0.22Lin, as shown in Fig. 5. The similar trends are found for all the three grids except little difference, so the grid Δx3is suitable for a correct simulation.

3. Results and discussion

3.1. Effects of hot jet on detonation wave structure

In this section, a deflection angle δ=20° in the combustor is selected and the inflow parameters are the same with Case 4,which corresponds to a weak overdriven state of ODW according to the R-H theory. Moreover, the position of hot jet is 0.855 Linaway from the tip of ramp. In general, there are two transition structures of shock wave to oblique detonation wave27: smooth transition and abrupt transition. Fig. 6(a) is the schematic of ODW structure only stabilized by a wedge.It consists of an oblique shock wave and an ODW behind.In such a configuration,the transition structure from the oblique shock wave to ODW is smooth, so a long distance(which consists of induction and transition zone28) that is far beyond the induction length is needed for an ODW formation. It is detrimental to the design of a short combustor. However, if a hot jet is injected to the induction zone perpendicular to the wall,the ODW abruptly forms in a shorter distance,as shown in Fig. 6(b). This abrupt transition is different from the previously smooth transition. The detailed structure of this abrupt transition from oblique shock wave to ODW is shown in Fig. 7.

Fig. 4 Discretization errors ε of induction zone in (induction zone along streamline of y=0.22Lin) varies with different mesh resolutions. (1 bar=100000 Pa).

Fig. 5 Variations of pressure and reaction progress along a streamline with different grid sizes.

Due to the high velocity behind the leading shock, the hot jet cannot deeply penetrate into the main flow, as shown in Fig.7.Hence,the hot jet injection in the numerical simulations acts as a gaseous wedge which induces a new oblique shock wave. This shock wave is strong enough to directly trigger the detonation and results in an abrupt transition. The initiation process of ODW with hot jet is a direct initiation triggered by the oblique shock wave, not a Deflagration-to-Detonation Transition (DDT) process. Teng et al.28reported three different shock configurations in different Mach numbers related to this abrupt transition, which are λ-shaped, X-shaped, and Y-shaped configurations.Furthermore,the transition structure caused by hot jet injection, as shown in Fig. 7, is a λ-shaped shock configuration,which consists of an induced shock wave,a reflected shock wave and a short Mach stem.

To further confirm the influence of this gaseous wedge on the flowfield, a real tiny wedge is placed at the same position instead of the hot jet. The angle θ1of the tiny wedge is 10°,and the horizontal length Lw=4.0 mm is the same as the width of the hot jet.The strong shock wave is also successfully initiated in front of the solid wedge,as shown in Fig.8.Hence,it is feasible to change the start point (or the position) of the ODW with the hot jet injection, and its effect is similar to

Fig. 6 Two different ODW structures caused by hot jet injection.

Fig. 7 Numerical schlieren29 image of abrupt transition caused by hot jet.

the plasma wedge induced by thermal choking10occurred in the arc discharge zone. Wang et al.10theoretically studied the mechanism of arc-discharge plasma without considering the viscous effects, they stated that the flux was almost zero in the arc discharge zone because of the thermal choking,and most of the flow would bypass the thermal choking region.Then the plasma wedge was formed because of thermal choking. Additionally, the chemical effect of the plasma seems not important. In our simulation, the local flow path is also changed by the gaseous wedge.A strong shock wave is induced near the position of hot jet injection, then the strong shock wave triggers the local combustion in the induction zone. The burned gas expands and an arc-shaped detonation wave is formed,then the main ODW gradually forms.Compared with the automatic ignition occurred in the case without hot jet injection, the transition point between the inert shock wave and detonation wave is largely moved upstream when the hot jet injection is utilized. Hence, it is more easily to design a shorter combustor with the aid of hot jet.

3.2. Influence of different hot jet injection positions on ODW

The mechanism of ODW initiation with the aid of hot jet injection has been discussed before. The arc-shaped detonation wave occurs after the transition point,but the angle of the detonation wave is not consistent with the flow condition. The angle of this arc-shaped detonation wave gradually decreases,until the standing ODW occurs.Compared with the case without hot jet injection, the instability of the detonation front is increased, more transverse waves that travel upstream are occurred, as shown in Fig. 9. In this section, the influence of hot jet injection on the angle of ODW is investigated, and the angle of wave structure after the arc-shaped detonation is selected to approximate the angle of ODW, as the dashed line shown in Fig. 9.

Fig. 8 ODW structures caused by a real tiny wedge.

For the four different flight conditions shown in Table 2,the angle of ODW η decreases as the position of hot jet injection close to the tip of wedge,as shown in Fig.10.Y axis is the ODW angle that is normalized by the ODW angle ηno-jetobtained in the same case without hot jet injection. X axis is the injection position that is normalized by the induction length Lin.The angle of ODW induced by the tiny wedge(tiny wedge indicates the result when the hot jet is replaced by a tiny wedge)is also decreased,as shown in Fig.8 and Fig.10.In the literature of arc discharge,the angle of the inert shock wave is decreased after the plasma wedge occurs.The reason is that the plasma layer covers the solid wedge and the angle of the real wedge changes,10thereby altering the angle of the inert shock wave. However, the wedge angle near the hot jet injection is changed in our simulations,but the angle away from the injection seems to be not changed,especially for the case with solid wedge shown in Fig.8.The mechanism of the change of ODW angle when the hot jet injection is utilized is unclear up to now.This change may be related to the abrupt transition from the inert shock wave to the ODW, the flow condition before the start point of main ODW is totally different. Not only the instability of ODW front is increased, but also the angle of the ODW is altered.

However, if the hot jet injection is too close to the tip of wedge, the decoupling phenomenon of detonation will occur in the downstream flow, as shown in Fig. 11. The position of injection is fixed at the distance of 0.167 Linaway from the tip of ramp,and the solid line represents the front of the flame approximately.A bow detonation wave,which is similar to the one stabilized by a spherical projectile studied in Ref.30,is successfully initiated at the position of injection, but the detonation wave gradually decouples as it is away from the hot jet.Although this bow detonation wave decouples at the downstream flow, the ODW eventually forms and is stabilized by the wedge. The main ODW occurs earlier than the case without hot jet injection, so the hot jet injection is beneficial to the initiation of ODW.

Fig. 9 Comparison of two different wave structures (with and without hot jet).

Fig. 10 Angles of overall ODW versus injection positions.

The detonation can be initiated and stabilized at a desired position that is shorter than the length of the induction zone,and the angle of detonation wave induced by hot jet is smaller than those cases only stabilized by a wedge. Therefore, it is possible to actively control the operating state of ODW in the combustor at the off-design flight conditions with the help of hot jet injection.Unfortunately,when the injection position of hot jet is too close to the tip of ramp, the wave structure which is similar to the prompt ODW (the induction zone is very short) reported by the Ref.6,7does not occur. The shock wave front and reaction front recouple again, and the main ODW forms downstream.

3.3. Influence of hot jet injection strength on ODW

A possible generation method of the hot jet injection is extracting the burned gas during the real flight. Generally speaking,the complexity and cost of the system hardware will be elevated if increasing the strength of hot jet. Besides, different strengths of hot jet injection result in different structures of ODW,and the key issue is how to initiate and stabilize a stable ODW with the minimum strength of the hot jet,in view of the complexity and cost of the system hardware. Here, a series of results with different injection velocities and pressures of hot jet are presented, especially for the cases that the strength of the hot jet is weaker than the CJ state.

Fig. 11 ODW structure when injection is close to tip of wedge(solid line is isoline of reaction process whose value is β=0.9).

Fig. 12 ODW structures with different injection velocities.

3.3.1. Effects of different hot jet injection velocities

In this section, a comparison of four different velocities of the hot jet is conducted, whose velocities are 1.0 VCJ, 0.8 VCJ, 0.7 VCJand 0.5 VCJrespectively.The pressure and temperature of hot jet injection are the same with the CJ values and the distance of hot jet away from the tip of wedge is 0.511 Lin.

While the angle of ODW for the case without hot jet is 42.35°, the ODW angles of the four cases with hot jet shown in Fig. 12 are 39.46°, 39.33°, 39.23° and 40.24° respectively.The minimum angle of ODW is the case whose injection velocity is 0.7 VCJ, as shown in Fig. 12(c), and it is obvious that there is no need to stabilize an ODW with a strong hot jet.However, the transition from oblique shock to ODW does not directly occur at the position of hot jet when it is too weak,as shown in Fig.12(d),but successfully stabilized by the wedge at the downstream flow. Therefore, the overall structure demonstrates a concave shape, which is different from the cases that the ODW is directly stabilized by the hot jet when the velocity of injection is high.

In order to adjust the height of ODW at the exit of combustor, a control methodology is necessary for the various flow conditions with a fixed geometry of the combustor,and ensure that the height of ODW is approximately equal to the height of combustor. Otherwise, both of the cases shown in Fig. 1 are detrimental to the performance of ODWE. The heights of ODW at the exit of combustor are 0.0759 m, 0.0715 m,0.0707 m and 0.0667 m respectively for the selected simulation domain in this study,as shown in Fig.12.Hence,the hot jet is an effective control method to adjust the height of ODW at the off-design flight conditions.

3.3.2. Effects of hot jet injection pressure

The injection pressure is another parameter to describe the strength of hot jet,and we will discuss the influence of different injection pressures on the overall structure of ODW in this section. For the hardware that generates hot jet injection, it may be easier to increase the injection pressure, compared with increasing the injection velocity. When the injection velocity is too weak to directly initiate an ODW at the position of hot jet, as shown in Fig. 12(d), higher injection pressure could compensate the weakness of low velocity and results in a successfully direct transition from the oblique shock wave to detonation. Two cases with different injection pressures of 1.5 PCJ, 2.5 PCJare investigated. The inflow of combustor is the same with Case 4. The velocity of hot jet is 0.5 VCJ, and the distance of hot jet away from the tip of wedge is 0.511 Linapproximately.

Fig. 13 ODW structures with different injection pressures.

Compared with the case shown in Fig. 12(d), it is clear to see that improving the pressure of hot jet injection is an effective method to suppress the decoupling phenomenon after the position of injection when the injection velocity is low, as shown in Fig. 13(a). The reason is that the gaseous wedge,as shown in Fig. 7, becomes stronger after the increase of the injection pressure,then the excitation of the gaseous wedge to the flowfiled is enhanced. A stronger induced shock wave forms and the ODW is triggered at the position of hot jet.Moreover, the λ-shaped wave structure, which is similar to the structure shown in Fig. 7, also occurs when the injection pressure increases to 2.5 PCJ, as shown in Fig. 13(b). Therefore, increasing the injection pressure is also an effective method to control the overall ODW structure when the injection velocity is weak.

4. Conclusions

With the conventional wedge to initiate and stabilize an ODW in the combustor of ODWE, there are challenges for ODWE operating at the optimum state under its flight conditions.One of the challenges is how to effectively initiate an ODW at a desired position and stabilize it over the entire flight time.Furthermore, it is also difficult to actively adjust the ODW with the conventional wedge, when the ODWE is working on off-design flight conditions. In this work, the hot jet injection is utilized to initiate and stabilize the ODW in a shorter distance, and the hot jet injection is placed in the induction zone of ODW.

(1) Compared with the automatic ignition cases without hot jet injection,the ODW is triggered in a shorter distance.The transition from inert shock wave to ODW is abruptly occurred, and it is different from the smooth transition.Hence,the minimum length for the formation of ODW can be effectively decreased for the four flight conditions, which is beneficial to the design of a short combustor. The reason is that the local flow path is altered by the injection after hot jet is added. The hot jet acts as a gaseous wedge which induces a new shock wave, and the detonation is consequently triggered behind the shock wave. Therefore, the transition structure at the position of hot jet is a λ-shaped wave configuration which consists of an induced shock wave, a Mach stem and an reflected shock wave.

(2) The angle of the ODW decreases as the position of injection approaches the tip of wedge.Therefore,the operating state of ODW in the combustor can be actively controlled by varying the hot jet injection at off-design flight conditions, so that the height of the ODW at exit of combustor can be guaranteed to approximately equal to the height of nozzle inlet.However,when the position of injection is too close to the tip of wedge, the abrupt transition which is similar to the prompt detonation does not occur.

(3) In general, the complexity and cost of the hot jet generation hardware could be reduced if the strength of hot jet is decreased. Then the influence of a weaker hot jet injection on the flowfield is investigated, the strength of the hot jet is weaker than the CJ state. The ODW can be stabilized when the velocity of injection is less than the CJ detonation velocity. However, the ODW is not directly stabilized at the position of hot jet injection when its velocity is too weak, and a concave shape of ODW occurs. While, the ODW is effectively stabilized at low injection velocity after the increase of the injection pressure. Hence, the hot jet is a flexible method to adjust the operating state of ODW in the combustor of ODWE by changing injection position, velocity and pressure.

Acknowledgements

This work was supported by the National Natural Science Foundation of China (Nos. 11572258, 91441201), NSAF(No. U1730134), Science Challenge Project (No.TZ2016001), National Key Laboratory for Shock Wave and Detonation Physics Research Foundation (No.6142A0304020617), the Fundamental Research Funds for the Central Universities (No. 3102017Ax006), and the opening project of State Key Laboratory of Explosion Science and Technology (Beijing Institute of Technology) (No. KFJJ19-13M).