Study on Influence of Functional Composition Distribution on Combustion Performance of a Modified Single Base Propellant

The modified single base propellant samples were prepared by impregnating blasting oil into single base grains and deactivating deterrent in water medium. The concentration distribution of functional compositions in this propellant was determined by using FTIR micro-spectroscopy. Its combustion performance was investigated by means of closed-bomb and interior ballistic tests. The results show that the concentration of NG distributes parabolically along the radius and the concentration of NA decreases from the surface to the centre exponentially. The deeper the NG impregnates, the slower the NA concentration decreases, the stronger the progressive combustion is and the better the interior ballistic performance is. When the depth corresponding to maximum NG concentration is about 1/2 of the web and the NA decreases slowly, the progressive combustion is the strongest and the interior ballistic performance is the best.     

Research on Effect of Adding Nanomaterial to Propellant on Gun Barrel

The barrel lifes of three small caliber rifles were tested by using the propellant with nanomaterial and the standard propellant respectively. The test results show that the service life increases observably due to adding nanomaterial to the propellant. Then, the influence of the nanomaterial on the tube was researched by splitting the two barrels tested and detecting their inner surfaces. It was found that the erosion of the barrel bore is reduced observably by using the propellant with nanomaterial. And it makes the volume and the size of the gun chamber change less. Therefore, the barrel life can be prolonged by adding the nanomaterial in the propellant.     

Numerical simulation of base flow with hot base bleed for two jet models

In order to improve the benefits of base bleed in base flow field, the base flow with hot base bleed for two jet models is studied. Twodimensional axisymmetric NaviereStokes equations are computed by using a finite volume scheme. The base flow of a cylinder afterbody with base bleed is simulated. The simulation results are validated with the experimental data, and the experimental results are well reproduced. On this basis, the base flow fields with base bleed for a circular jet model and an annulus jet model are investigated by selecting the injection temperature from 830 K to 2200 K. The results show that the base pressure of the annular jet model is higher than that of the circular jet model with the changes of the injection parameter and the injection temperature. For the circular jet model, the hot gases are concentrated in the vicinity of the base. For the annular jet model, the bleed gases flow into the shear layer directly so that the hot gases are concentrated in the shear layer. The latter temperature distribution is better for the increase of base pressure. Copyright . 2014, China Ordnance Society. Production and hosting by Elsevier B.V. All rights reserved.     

The Application of Erosive Burning to Propellant Charge Interior Ballistics

Erosive burning is a common burning phenomenon of the gunpowder with inner holes. The actual combustion law of the gunpowder with inner holes can be changed by erosive burning. Pressure difference between the inner and the outer of hole caused by loading density variation of the propellant charge makes erosive burning occur at inner holes during in-bore burning. The effect of erosive burning on burning speed of the propellant is studied by using the effects of flow rate, heat transfer and erosion of the combustion gas in inner holes on burlaing rate. The mathematic model of erosive burning of the propellant is established. The effects of the factors such as loading density, inner hole size and grain length on erosive burning and interior ballistic performance are analyzed . The method to improve the bore pressure for small charge mass and small firing range by erosive burning is proposed.     

A Measuring Method on Moment of Inertia of Large-scale Ammunition

A compound pendulum based measurement method is put forward and the relevant equipment is designed. By using the variation of angle with the time acquired by an angular displacement sensor, the moment of inertia is obtained through the numerical solution of certain equations, which are deduced from the phase-plane analysis of compound pendulum. The influences of both friction and air resistance on the compound pendulum are already taken into consideration without estimating and measuring the resistances in advance. With this method, the to-be-measured object can be positioned and fixed easily and safely. Numerical simulations show a favorable precision of this method.     

Experimental investigation of a cook-off temperature in a hot barrel

The experimental investigations of the effect of contact time/temperature on initiating the cook-off using 7.62 mm calibre cartridge cases （CC） were conducted previously. These cartridges were filled with commercial off-the-shelf （COTS） double based （DB） propellant （Bulls Eye） and were loaded in a hot chamber. The thermal explosion temperature is of great significance to both weapon designers and safety inspectors as it provides the operational limit and safe operating temperature. For CC under test, it was found that the cook-off temperatures of this propellant were encountered with the heat transfer profile of the simulated gun barrel between 151.4 ℃ and 153.4 ℃, with a reaction occurring in less than 300 s after the round was chambered. Usefully, each experiment was found to be consistent and repeatable.     

Analysis of Heat Transfer in Actively Cooled Compound Gun Barrel

when a gun fires, a large amount of heat is brought in the barrel. Erosion/wear and security problems(self ignition of the propellant) associated with this high thermal energy have to be solved owing to the use of higher combustion gas temperature for improved cannon performance and firing at the sustained high rates, Barrel cooling technologies are the effective measures for addressing this issue, In view of the importance of having knowledge of the heat flux, an approach to calculate heat flux based on measurements was presented and validated. The calculated heat flux is used as the inner boundary condition for modeling heat transfer in a 155 mm mid-wall cooled compound gun barrel, Theoretical analysis and simulated results show that natural air cooling is dramatically slower than the forced liquid mid-wall cooling, accordingly wear life of actively cooled barrel is increased and barrel overheating is prevented,     

A Novel Artificial Superposition Compound Eye

A new artificial superposition compound eye model is presented based on micro-lens array. In all compound eyes, it has the advantages of small volume, light weight, wide FOV, high sensitivity and much higher energy utilization ratio. Nevertheless, its structure is relatively complicated, especially the GRIN medium in the crystalline cone. Therefore, the modeling, analysis and fabrication for it are burdensome. In the established model, the GRIN is replaced by a curved micro-lens array. Thus, the modeling, analysis and optimization process are simple, and the components of artificial superposition compound eye are easy to be fabricated. The system is modeled by ZEMAX software. With the help of raytracing, its principle is analyzed, and the sensitivity comparison between the superposition compound eye and the apposition compound eye is done. The model＇ s validity is proven.     

Effects of Plasticizers,Antioxidants and Burning Rate Modifiers on Aging Performance of the HTPB/HMDI Composite Solid Propellant

The effects of plasticizers,antioxidants and burning rate modifiers on the aging performance of the composite solid propellant based on hydroxyl-terminated polybutadiene(HTPB)/hexamethylene diisocyanate(HMDI)were explored by apply-ing an accelerated aging program for 90 day at 70 ℃. The HTPB propellant matrix with the diisooctyl sebacate(DOS)as plasti-cizers and diisooctyl azelate(DOZ), antioxidants as N,N ′-Diphenyl-p-phenylenediamine(AO) and 2,2′-methylenebis(4-methyl-6-tert-butylphenol)(cyanox 2246)and burning rate modifiers as barium ferrite(BF),copper chromites(CC)and fer-ric oxide(FO)were varied. Results show that sample(S1)which based on DOS decreases the stress value and increases the strain value which considered to be an excellent start for aging program. Sample(S3)containing AO presents the higher resis-tance to oxidation showing the better performance that reflects on increasing the shelf life of the composite solid propellant mo-tor. Sample(S5)which based on BF enhances the ballistic performance among over the other tested two samples. The accelerat-ed aging program allowed us to estimate the motor in-service lifetime.     

Innovative Metallized Formulations for Solid Rocket Propulsion（英）

Several metallized solid rocket propellants,AP/Metal/HTPB in the ratio 68/18/14,were experimentally analyzed at the Space Propulsion Laboratory of Politecnico di Milano.Effects of the metals(micrometric and nanometric Al,B,Mg,and a variety of dual metals) on the performance of the propellant were studied and contrasted to a conventional micrometric aluminum(30 μm average grain size) taken as reference.It is shown that the propellant microstructure plays a fundamental role in controlling the critical aggregation/agglomeration phenomena occurring below and near the burning surface.Two specific effects of microstructure in terms of steady burning rate and average agglomerate size are illustrated.     

发射药连续化生产模型研究

为研究发射药连续化生产技术,以发射药溶塑制造工艺为背景,建立发射药连续化生产模型.利用制造发射药的物料在工序中的流动速度,研究了发射药连续化生产各工序物流匹配关系和工艺设备匹配关系,通过对发射药连续化生产工艺单元物料流速进行分析,建立了发射药连续化生产线物料流速为特征的发射药连续化生产模型,并以某种发射药制造为例研究发射药连续化生产模型在该发射药连续化生产中的应用.结果表明:该模型可用于发射药连续化生产工艺优化,解决离散工序与连续工序的连续化结合问题.     

发射装药发射安全性评估方法

为解决高性能火炮发射装药发射安全性问题,对发射装药发射安全性评估方法进行研究。揭示了发射装药引起膛炸的机理,建立了发射装药燃烧与力学环境试验方法、发射装药动态挤压破碎试验方法、发射装药动态活度试验方法,并提出了发射装药发射安全性评估方法。该方法为科学评估发射装药发射安全性提供了理论依据与技术手段。     

胶体推进剂的研究与应用

肢体推进剂兼具液体推进剂和固体推进剂的优点，因而近半个世纪以来国内外都在努力研制这种新概念推进剂，并由此发展先进的肢体推进技术，即“灵巧”推进技术。美国已成功地进行了肢体推进技术的地面试验和飞行试验。从理论上说，任何液体推进剂都可以制成肢体推进剂。因此，肢体推进剂既可以用于单组元推进系统，也可以用于双组元推进系统；既可以用于运载火箭，也可以用于武器系统。本文论述肢体推进剂和肢体推进技术的发展趋势和研究目标，简要介绍国内研究概况，并提出今后的研究设想。     

增能钝感单基药的燃烧特性

为了优化单基药的弹道性能,对其进行了改性研究。对11/7单基药进行硝化甘油浸渍及聚酯类材料阻燃处理,得到一种增能钝感单基药。利用点火试验装置及密闭爆发器对该类型发射药进行了点火及燃烧性能试验,点火试验结果表明:与原单基药对比,增能后的发射药点火延迟时间从5.8ms缩短到4.1ms,增能钝感后的发射药点火延迟时间从5.8ms延长到45.5ms以上;密闭爆发器试验中增能钝感前后发射药燃烧时间与点火试验中点火延迟时间的变化趋势相同(原单基药为9.5ms,增能后为8.5ms,增能钝感后为10.86ms以上),增能后的发射药与原单基药相比具有一定的渐增性燃烧特性。     

XLDB与NEPE推进剂催化燃烧性能的研究

制备了几种含燃烧催化剂的XLDB和NEPE推进剂,利用静态靶线法测试了其燃速。结果表明,对XLDB推进剂,一元水杨酸铅与一元水杨酸铜复配,二者比例为1.5∶0.5时,可使XLDB推进剂压力指数降低27.1%;其它铅、铜盐复配,只增加XLDB推进剂的燃速,对降低其压力指数效果不大;一元水杨酸铅与钼酸镍或氧化钍复配,燃速和压力指数高于和一元水杨铜复配;钼酸镍与其它燃速催化剂复配,不能降低压力指数,但燃速略有提高。对NEPE推进剂,碳酸铅的用量增加,有利于压力指数的降低;多组元燃烧催化剂对NEPE推进剂燃速和压力指数有一定影响,但和双组元的相比,并无大的差异。     

发射装药发射安全性评定方法研究

发射装药发射安全性问题严重制约现代火炮武器的发展,成为各军事强国竞相攻关解决的重大理论与技术难题。从揭示发射装药引起膛炸的机理入手,通过理论、计算、试验3个方面连续17年的系统深入研究,引入起始动态活度比新概念,建立了我国首个基于发射装药起始动态活度比的发射装药发射安全性评定方法兵器行业标准和国家军用标准。文中包括：发射装药发射安全性评定原理、发射装药发射安全性评定流程、发射装药膛内力学环境试验方法、发射装药动态挤压破碎试验方法、发射装药起始动态活度比试验方法、发射装药发射安全性判据的确定方法、发射装药发射安全性评定方法,并成功用于工程实践,为科学评估发射装药发射安全性提供了系统的理论依据、技术手段和技术标准。     

固体火箭推进剂过保温后力学性能试验研究

为了研究固体火箭推进剂过保温后的力学性能,在保温温度为50 ℃的条件下,对NEPE推进剂哑铃型试件进行了3个不同拉伸速率下10组保温时间下的拉伸试验。试验结果表明,与未保温的NEPE推进剂试件相比,保温之后NEPE推进剂的强度有一定的提高,延伸率出现明显的下降; NEPE推进剂试件的保温时间越长,抗拉强度越大; 在保温时间相同的情况下,保温次数越多,抗拉强度越大; 保温时间和保温次数对NEPE推进剂的延伸率没有影响。     

镁铝金属粉对含硼富燃推进剂燃烧性能及硼氧化效率的影响

为了确定镁铝金属粉对含硼富燃推进剂燃烧性能和硼氧化效率的影响,用靶线法测定三种配方含硼富燃推进剂在0.5,1.0,1.5 MPa三种压力条件下的燃速,采集相应的燃烧残渣,用化学分析法测定了三氧化二硼(B2O3)和总硼(B)含量,计算出硼的氧化效率。实验结果表明,镁粉含量对推进剂燃烧性能有明显影响。推进剂中B的含量为30%,并固定其他组分,金属粉含量为6%,改变镁粉和铝粉比例,镁粉0%,3%,6%,相应铝粉为6%,3%,0%。当镁粉含量较高时,推进剂燃速较高,压力指数也较高;镁粉含量低时,燃烧残渣中B2O3含量较高,而镁粉含量高时,燃烧残渣中B2O3含量较低;且随着压力的增高,残渣中B2O3的含量降低;硼的氧化效率随镁含量的增高和压力升高而降低。镁粉可抑制硼的氧化反应,使硼氧化效率降低,提高推进剂燃速和压力指数。     

浇铸型高能CMDB推进剂的力学性能

研究了硝化棉种类和含量、高氯酸铵粒径,以及双基球和黑索今含量等对复合改性双基(CMDB)推进剂力学性能的影响。结果表明,随着含氮量12.0%的NC的降低,CMDB推进剂20℃和50℃下的拉伸强度和延伸率均显著降低。在CMDB推进剂中添加适量含氮量13.0%的NC和12.6%的NC均有助于提高推进剂拉伸强度;含氮量13.0%的NC不利于改善推进剂的延伸率;而含氮量12.6%的NC有助于提高推进剂的低温延伸率,但对推进剂高温延伸率影响不显著。在CMDB推进剂中添加适量的双基球对提高推进剂的拉伸强度和延伸率均有利。AP的粒径对CMDB推进剂力学性能影响显著,小粒径的AP有利于提高推进剂的拉伸强度,而大粒径的AP有利于改善推进剂的延伸率。随着RDX取代AP量的逐渐增大,CMDB推进剂在高温和常温下的拉伸强度先增大后减小,而延伸率先增减小后增大。     

一种低烧蚀高渐增性发射药的研究

采用“浸渍-钝感”工艺制得改性单基发射药.用烧蚀管试验表征了该发射药的烧蚀.采用密闭爆发器研究了该发射药的静态燃烧性能,以857-30 mm制式弹道炮研究了发射药在膛内的动态内弹道性能.结果发现,与制式单基发射药相比较,制得的改性单基发射药的烧蚀量降低了16.4％,燃烧渐增因子P,由0.035提高到0.445,初速从8...