Plastic Propellant Research Articles

Investigation of 3D Printed Underwater Thruster Propellers Using CFD and Structural Simulations

Unmanned Surface Vehicles (USV) and Autonomous or Remotely Operated Underwater vehicles (AUV, ROV) are developing and spreading rapidly in various industries. A common feature of these vehicles is that they are propelled by small plastic (or metal) propellers in most cases. Additive manufacturing can offer an excellent opportunity for rapid prototyping and the development of new models. This paper aims to investigate the fundamental aspects to be considered in the geometric design and manufacturing of small (diameter less than 100 mm) PLA (Polylactic acid) propellers 3D-printed using Fused Filament Fabrication (FFF) technology. In-service deformation of 3D-printed PLA ducted propellers with average geometry was investigated to determine the effect on the thrust and torque on the blades. For this purpose, one-directional FSI (Fluid Solid Interaction) simulations were performed using CFD (Computational Fluid Dynamics) and structural simulations. The propeller CAD geometries were generated using an in-house MATLAB script. The variable parameters of each version are the thickness, skew, and rake of the propeller blades. For the structural simulations, it was considered that the material properties of PLA parts printed with FFF technology depend on the print orientation. The results of the simulations show that except for extreme geometries (e.g., thin blades, skew, or rake more than 10°), the deformation of small PLA ducted propellers is not significant. CFD studies of the deformed geometries have shown that the resulting deformation has no significant effect on the thrust and torque of the propeller and thruster.

Quadcopter based emergency medikit delivery system for hill stations

Now-a-days UAV’s are more common for search, rescue and surveillance. A quad copter UAV system is proposed to be used for aerial transportation of medicine. A Quadcopter has a drive chassis having a propeller, ESC, motor, frames and battery. Quadcopter is supported with GPS to know the exact position. To know the exact location and delivering medicine to accident area, an audio and video system is used. The quad frame built from quality materials, which are reinforced and much more stronger, this reduces arm breakage. A set of two plastic propellers, one normal and one pusher (reverse) to rotate and lift up the quadcopter. The brushless out-runner will provide more power with its high efficiency, long run times. The ESC includes programmable motor braking, soft start for helicopters and planes, timing, throttle input range and low-voltage cutoff. Lithium-Polymer (Li-Po) battery for very light weight, small size and durability without losing charging capacity. The whole quadcopter process can be monitored and controlled by a remote control system, quadcopter will capture the live video and current status can be seen visualized and provides information about all the other exact condition in real time.

Formulation and Characterization of a New Nitroglycerin‐Free Double Base Propellant

AbstractDouble base propellants composed of nitrocellulose (NC) and nitroglycerine (NG) are widely used. However, the inclusion of liquid NG presents both stability and performance problems: the NG may migrate from the propellant in storage, and it softens the propellant at high inclusion levels. In this work, the novel nitrate ester 1,4‐dinitrato‐2,3‐dinitro‐2,3bis(nitratomethylene) butane (SMX) is considered as a replacement for NG in a double base propellant. Thermochemical calculations indicate improved performance when compared with the common double base propellant JA2 at SMX loadings above 40 wt‐%. Also, since SMX is a room temperature solid, migration may be mitigated. Both unplasticized and plasticized propellants were formulated to enable the study of the interaction of SMX with nitrocellulose. Thermal analysis of unplasticized propellant showed a distinct melt‐recrystallization curve, which indicates that a solid phase solution is being formed between SMX and NC, and that SMX would not act as plasticizer. Analysis of propellant prepared with diethyleneglycol dinitrate (DEGDN) plasticizer indicates that the SMX is likely dissolved in the DEGDN. The plasticized material also showed similar hardness and modulus to JA2. Safety characterization showed that sensitivity is similar to JA2. In short, replacing NG with SMX results in a new family of propellants with acceptable safety characteristics and which may also offer improved theoretical performance.

Illustrating the Use of Statistical Experimental Design and Analysis for Multiresponse Prediction and Optimization

ABSTRACT This article illustrates statistically designed experiments and their analysis with plastic propellers in the typical prototype development situation where there are multiple responses. We compare analyses of unreplicated and replicated experiments. We also consider prediction and two methods for multiple response optimization based on constrained optimization and desirability functions. Details are provided so that the propeller experiment can be carried out in a short course or workshop.

Studies on Triple Base Gun Propellant Based on Two Energetic Azido Esters

Triple base propellant is the workhorse propellant because it possesses several advantages like reduced flash, flame temperature, and erosion of the barrel as compared to double and single base propellant. Hence, efforts are going on worldwide to increase its performance by increasing its energy using energetic plasticizers and binders. In the present article, nonenergetic plasticizer dibutyl phthalate (DBP) is replaced by two energetic azido ester plasticizers, tris(azido acetoxy methyl) propane (TAAMP) and bis(azido acetoxy) bis(azido methyl) propane (BABAMP), in triple base composition and their different properties are studied. Experimental closed vessel (CV) results (loading density 0.2 g/cm3) clearly indicate that the triple base composition with 2% DBP has force constant 1018 J/g, which is increased to 1026 and 1030 J/g on replacement of DBP by 1 and 2% TAAMP, respectively. Mechanical properties of propellant compositions containing 1 and 2% TAAMP (compression strength 279 and 291 kgf/cm2, percentage compression 11.2 and 10.5, respectively) are also better than those of composition containing DBP (compression strength 275 kgf/cm2 and 10.3% compression). Similarly, 1 and 2% replacement of DBP by BABAMP shows further rise in energy (1032 J/g, 1038 J/g respectively) than that of compositions containing 1 and 2% TAAMP. These two compositions also exhibit better mechanical properties (compression strength 311.2 and 312.3 kgf/cm2, % compression 11.0 and 10.5, respectively) than compositions containing 1 and 2% TAAMP. The differential thermal analysis (DTA) results brought out the fact that the compositions containing energetic plasticizers revealed maximum decomposition temperature in the range of 172–174°C which is close to DBP plasticized triple base gun propellants (174°C). The energetic plasticized propellant compositions of both (TAAMP and BABAMP) showed sensitivity data in the range of (H50 19 to 22 cm, F of I 25 to 29 and friction insensitivity 19.2 kg) acceptable limit for gun propellant.

Using metallic resin and aluminum alloy molds to manufacture propellers with RP/RT technique

PurposeThis purpose of this study is to investigate an effective method to manufacture propellers.Design/methodology/approachThe investment casting process and injection molding process have been applied separately to the rapid prototyping/rapid tooling (RP/RT) to obtain metal (Al‐Si alloy) propellers and plastic (Acrylonitrile butadiene styrene – ABS) propellers. The two different manufacturing processes were compared following the same master model (MM). The Moldflow software is used to optimize the experimental parameters of the molding. Furthermore, a gypsum type of powder is used to produce the RP MM of the propeller according to the Pro‐E software. The RP MM then is filled with a metallic resin material (at room temperature) to obtain a wax mold. Then, this wax mold was coating by dipping the ZrO2 slurry to improve heat resistant ability, and following solidification, and then filled with metal alloy to obtain metal (Al‐Si alloy) propellers. Another process, the RP MM by dipping the ZrO2 slurry to increase the heat resistance and then is filled with aluminum alloy and an injection mold can be obtained, the plastic (ABS) propellers can be duplicated. To ensure the precision of dimension and improves the surface roughness for the RT (metallic resin mold and aluminum alloy mold), the contour of the duplicated molds were milling with the high‐speed CNC manufacturing program.FindingsThe advantage of this process is that combining the RP/RT system with the high‐speed CNC machining center enables easy production of injection molds.Originality/valueThis process provides engineers with a quick way to fabricate parts and modify the designs. This study demonstrates that this process provides a practical way to fabricate parts and saves the cost and time which increases market competition. The molds with high precision and good surface roughness were duplicated by the rapid‐prototype technique. Furthermore, this investigation demonstrates that: if the product contains special shapes? The material requires a large amount of cutting? or In the case of expensive and hard to machine materials, the proposed process is the best choice to duplicate cost‐effective mold.

Determination of plastoviscosity and the flow curve equation of stiff pastes by parallel plate plastometry

A parallel plate plastometer has been used to measure the plastoviscosity of a plastic propellant, which is a heavily loaded stiff paste previously (1) considered to approximate to a shear-hardeningBingham solid.

Combustion instability studies with plastic propellant

The eifect of compositional changes on the stability of combustion of plastic propellent, based upon ammonium perchlorate and polyisobutene, is investigated using a 2-in.-diam T burner for the frequencies 0.7-4.0 kHz at 1000 psig. Oxidizer particle size can have a pronounced effect both on the acoustic response and on the maximum pressure amplitude which can be sustained in the T burner, whereas changes in the oxidizer-fuel ratio have little effect. Titanium dioxide, usually added to plastic propellent to stabilize combustion, is shown to have a dual effect: the acoustic response is reduced and the gas phase particle damping is promoted. Finally, the effect of lithium fluoride and copper chromate on combustion instability is examined. An inverse correlation, which is frequency dependent, is observed between propellent burning rate and both the acoustic response and the maximum pressure amplitude sustained in the T burner.

The ultrasonic testing of boost motors

The boost motors of British guided weapons contain a plastic propellant bonded to a steel case. Bonding defects can cause catastrophic failure during a firing and so the case-to-propellant bond is tested by comparing the decay patterns of an ultrasonic pulse transmitted into the case. Extremely short-pulse probes have been developed that avoid interference effects and give a clear series of multiple echoes from the thinnest case. Fully automatic scanning and recording systems with focused immersion probes have also been designed