Design, Production and Evaluation of 3D-Printed Mold Geometries for a Hybrid Rocket Engine

Grefen, Benedict; Becker, Johannes; Linke, Stefan; Stoll, Enrico

doi:10.3390/aerospace8080220

Cited by 13 publications

(10 citation statements)

References 13 publications

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“…He observed improved performance compared to the baseline tests and a reduced O/F shift as anticipated [129]. Instead of printing the fuel itself, it is also feasible to print the mold of the fuel grain around which the fuel (HTPB) is casted [130]. After casting, the mold, whose material is polyvinyl alcohol, can be dissolved in water, leaving only the fuel grain with the desired and complex port geometry.…”

Section: Advanced Fuel Port Profiles and Combustion Chambersmentioning

confidence: 87%

Evaluation of Regression Rate Enhancing Concepts and Techniques for Hybrid Rocket Engines

Glaser

Hijlkema

Anthoine

2022

Aerotec. Missili Spaz.

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The low regression rate of Hybrid Rocket Engines (HREs) is one prominent characteristic that is addressed in most abstracts concerning hybrid propulsion. Over the years, researchers developed and investigated numerous ways to tackle the low regression rate problem of HREs. This article is a collection and assessment of these diverse methods and designs. It allows for a quick overview of the different mechanisms that are being employed and can serve both as information and inspiration. The enhancement ideas are grouped together as (a) adjustments to the solid fuel chemical properties, (b) advanced injection methods and concepts and (c) improving the combustion chamber design. These different techniques are discussed and their individual impact on the regression rate is assessed both qualitatively and quantitatively. All methods that are presented come with a different set of advantages and disadvantages, making the regression rate enhancement a trade-off problem. In our view, the most promising designs and methods are those that only call for minor adjustments to the HRE design, as they can be also added to already existing engines. Above all, it is to be said that regression rate enhancing techniques that change the unique features of HREs (namely safety, simplicity and low cost) are to be employed with caution. Only if the achievable regression rate increase is justifying the implications for the HRE in the envisioned use-case, these concepts represent promising alternatives to the status quo.

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Section: Advanced Fuel Port Profiles and Combustion Chambersmentioning

confidence: 87%

Evaluation of Regression Rate Enhancing Concepts and Techniques for Hybrid Rocket Engines

Glaser

Hijlkema

Anthoine

2022

Aerotec. Missili Spaz.

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show abstract

“…However, additive manufacturing (3D printing) can be used to produce an intricate negative mold in a dissolvable thermoplastic material such as polyvinyl alcohol (PVA). Researchers have used 3D printed PVA molds in applications such as microfluidic channels 10 , biocompatible gelatin scaffolds 11 , ceramic injection molding of parts 12 , and rocket engine components 13 .…”

Section: Figure 1 Neuron Components Of Pyramidal Cellmentioning

confidence: 99%

3D Printing of Flexible, Scaled Neuron Models

Habbal

Farhat

Khalil

et al. 2023

Preprint

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Microscopy-based 3D neuronal reconstructions are freely available online, including in the NeuroMorpho.Org file repository. Each neuron’s dendritic structure is intricate and diverse, making it challenging to produce accurate physical 3D models for instruction or visualization. This work examines several methods for producing 3D models of neuronal reconstructions and compares their cost and accessibility. In response to high cost of direct 3D printing methods, we develop a new casting method which uses 3D-printed, single-use dissolvable molds and achieves lower cost for producing 3D neuron models. The casting method uses a consumer-grade desktop fused filament fabrication 3d printer, water-soluble polyvinyl alcohol filament, and a two-part casting material such as polyurethane resin or silicone rubber. Physical models of a diverse set of neuron morphologies including purkinje, pyramidal, medium spiny, and retinal ganglion cells were produced using the casting method with good fidelity to the neuronal reconstruction file and sufficient detail and strength for hands-on use in neuroscience education and research. The average cost of producing the four neuron models using the proposed casting method was reduced by 58% relative to the cost of using the least expensive 3D printing method by a service provider. Production time for one neuronal model using the proposed method was found to be in the range of 1-3 days while service-provided neurons required a minimum of a week from order placement to delivery.

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“…Three-dimensional (3D) printing is a promising field of emerging technology for fabricating complex and customized structures [1,2]. Furthermore, it is used for research and commercial purposes for the recycling of thermoplastic composite materials [3,4] and smallquantity customized production, such as patient-specific tooth implants [5] and discontinued engine parts [6]. Although 3D printing can provide an on-demand manufacturing process, it is difficult to build multi-functional products due to its single-material-based architecture.…”

Section: Introductionmentioning

confidence: 99%

Three-Dimensionally Printed Expandable Structural Electronics Via Multi-Material Printing Room-Temperature-Vulcanizing (RTV) Silicone/Silver Flake Composite and RTV

Lee

Park

et al. 2023

Polymers

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Three-dimensional (3D) printing has various applications in many fields, such as soft electronics, robotic systems, biomedical implants, and the recycling of thermoplastic composite materials. Three-dimensional printing, which was only previously available for prototyping, is currently evolving into a technology that can be utilized by integrating various materials into customized structures in a single step. Owing to the aforementioned advantages, multi-functional 3D objects or multi-material-designed 3D patterns can be fabricated. In this study, we designed and fabricated 3D-printed expandable structural electronics in a substrateless auxetic pattern that can be adapted to multi-dimensional deformation. The printability and electrical conductivity of a stretchable conductor (Ag-RTV composite) were optimized by incorporating a lubricant. The Ag-RTV and RTV were printed in the form of conducting voxels and frame voxels through multi-nozzle printing and were arranged in a negative Poisson’s ratio pattern with a missing rib structure, to realize an expandable passive component. In addition, the expandable structural electronics were embedded in a soft actuator via one-step printing, confirming the possibility of fabricating stable interconnections in expanding deformation via a missing rib pattern.

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Design, Production and Evaluation of 3D-Printed Mold Geometries for a Hybrid Rocket Engine

Cited by 13 publications

References 13 publications

Evaluation of Regression Rate Enhancing Concepts and Techniques for Hybrid Rocket Engines

Evaluation of Regression Rate Enhancing Concepts and Techniques for Hybrid Rocket Engines

3D Printing of Flexible, Scaled Neuron Models

Three-Dimensionally Printed Expandable Structural Electronics Via Multi-Material Printing Room-Temperature-Vulcanizing (RTV) Silicone/Silver Flake Composite and RTV

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