Purpose

This paper aims to determine the regression rate using wax fuels for three different grain configurations and find a suitable grain port design for hybrid rocket application.

Design/methodology/approach

The design methodology of this work includes different grain port designs and subsequent selection of solid fuels for a suitable hybrid rocket application. A square, a cylindrical and a five-point star grained were designed and prepared using paraffin and beeswax fuels. They were tested in a laboratory-scale rocket with gaseous oxygen to study the effectiveness of solid fuels on these grain structures. The regression rate by static fire testing of these wax fuels was analyzed.

Findings

Beeswax performance is better than that of paraffin wax fuel for all three designs, and the five-slotted star fuel port grain attained the best performance. Beeswax fuel attained an average regression rate ≈of 1.35 mm/s as a function of oxidizer mass flux Gox ≈ 111.8 kg/m² s and for paraffin wax 1.199 mm/s at Gox ≈ 121 kg/m² s with gaseous oxygen. The local regression rates of fuels increased in the range of 0.93–1.194 mm/s at oxidizer mass flux range of 98–131 kg/m² s for cylindrical grain, 0.99–1.21 mm/s at oxidizer mass flux range of 96–129 kg/m2s for square grain and 1.12–1.35 mm/s at oxidizer mass flux range of 91–126 kg/m² s for a star grain. A complete set of the regression rate formulas is obtained for all three-grain designs as a function of oxidizer flux rate.

Research limitations/implications

The experiment has been performed for a lower chamber pressure up to 10 bar.

Originality/value

Different grain configurations were designed according to the required dimension of the combustion chamber, injector and exhaust nozzle of the design of a lab-scale hybrid rocket, and input parameters were selected and analyzed.

中文翻译：

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混合火箭发动机中具有不同颗粒配置的石蜡和蜂蜡-Gox的回归率性能

目的

本文旨在确定使用蜡燃料对三种不同谷物配置的回归率，并为混合火箭应用找到合适的谷物端口设计。

设计/方法/方法

这项工作的设计方法包括不同的谷物端口设计和随后为合适的混合火箭应用选择固体燃料。使用石蜡和蜂蜡燃料设计和制备了方形、圆柱形和五点星形颗粒。它们在带有气态氧的实验室规模火箭中进行了测试，以研究固体燃料对这些颗粒结构的有效性。分析了这些蜡燃料的静态燃烧测试的回归率。

发现

蜂蜡的性能在三种设计中均优于石蜡燃料，五槽星形燃料端口纹获得最佳性能。作为氧化剂质量通量 Gox ≈ 111.8 kg/m ² s的函数，蜂蜡燃料获得了 ≈ 1.35 mm/s 的平均回归率，而石蜡燃料在 Gox ≈ 121 kg/m ² s 和气态氧下达到了 1.199 mm/s 。在氧化剂质量通量范围为 98-131 kg/m ² s 时，燃料的局部回归率在 0.93-1.194 mm/s 范围内增加，对于圆柱形颗粒，在氧化剂质量通量范围为 96-129 时增加 0.99-1.21 mm/s kg/m2s 方形颗粒和 1.12-1.35 mm/s，氧化剂质量通量范围为 91-126 kg/m ²s 表示一颗星粒。对于所有三晶粒设计，作为氧化剂通量率的函数获得了一套完整的回归率公式。

研究限制/影响

该实验是在高达 10 bar 的较低腔室压力下进行的。

原创性/价值

根据实验室混合火箭设计所需的燃烧室、喷射器和排气喷嘴的尺寸设计了不同的颗粒配置，并对输入参数进行了选择和分析。