Regression Rate Characteristics of Paraffin-based Fuel under Swirled Oxidizer Flow

2012 ◽  
Author(s):  
Keij Shinohara ◽  
Ichiro Nakagawa
Keyword(s):  
Regression Rate

A Visual Study of the Combustion of High-Regression Rate and Classical Hybrid Rocket Fuels

2015 ◽  
Author(s):  
Elizabeth T. Jens ◽  
Victor A. Miller ◽  
Flora S. Mechentel ◽  
Brian J. Cantwell ◽  
Scott Hubbard
Keyword(s):  
Hybrid Rocket ◽  
Regression Rate ◽  
Visual Study

scholarly journals Challenges of Ablatively Cooled Hybrid Rockets for Satellites or Upper Stages

Aerospace ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 190
Author(s):  
Francesco Barato
Keyword(s):  
Combustion Chamber ◽  
Solid Fuel ◽  
Diameter Ratio ◽  
Propulsion System ◽  
Burning Time ◽  
Regression Rate ◽  
Hybrid Propulsion ◽  
Deep Impact ◽  
Time Ratio ◽  
Hybrid Rockets

Ablative-cooled hybrid rockets could potentially combine a similar versatility of a liquid propulsion system with a much simplified architecture. These characteristics make this kind of propulsion attractive, among others, for applications such as satellites and upper stages. In this paper, the use of hybrid rockets for those situations is reviewed. It is shown that, for a competitive implementation, several challenges need to be addressed, which are not the general ones often discussed in the hybrid literature. In particular, the optimal thrust to burning time ratio, which is often relatively low in liquid engines, has a deep impact on the grain geometry, that, in turn, must comply some constrains. The regression rate sometime needs to be tailored in order to avoid unreasonable grain shapes, with the consequence that the dimensional trends start to follow some sort of counter-intuitive behavior. The length to diameter ratio of the hybrid combustion chamber imposes some packaging issues in order to compact the whole propulsion system. Finally, the heat soak-back during long off phases between multiple burns could compromise the integrity of the case and of the solid fuel. Therefore, if the advantages of hybrid propulsion are to be exploited, the aspects mentioned in this paper shall be carefully considered and properly faced.

Engineering Model for Hybrid Fuel Regression Rate Amplification Using Helical Ports

2017 ◽  
Vol 33 (2) ◽  
pp. 398-407 ◽  
Author(s):  
Stephen A. Whitmore ◽  
Sean D. Walker
Keyword(s):  
Engineering Model ◽  
Regression Rate

scholarly journals Application of Rainbow Thermometry to the Study of Fuel Droplet Heat-Up and Evaporation Characteristics

1996 ◽  
Author(s):  
Subramanian V. Sankar ◽  
Dale H. Buermann ◽  
William D. Bachalo
Keyword(s):  
Vaporization Rate ◽  
Fuel Droplet ◽  
Controlled Experiments ◽  
Regression Rate ◽  
Droplet Vaporization ◽  
Fuel Droplets ◽  
Spray Flame ◽  
Polydisperse Flow ◽  
Phase Doppler Particle Analyzer

Advanced, non-intrusive, laser-based diagnostics are being developed for simultaneously measuring the size, velocity, temperature, and instantaneous regression rates of vaporizing/burning fuel droplets in polydisperse flow environments. The size and velocity of the droplets are measured using a conventional phase Doppler particle analyzer (PDPA), whereas the droplet temperatures are simultaneously measured with a rainbow thermometer. This integrated diagnostic has been applied to the study of fuel droplet heat-up characteristics in a swirl-stabilized kerosene spray flame. It has also been shown that a novel extension of rainbow thermometry can be used to additionally extract the instantaneous droplet vaporization rate. The feasibility of measuring the instantaneous regression rate has also been demonstrated using controlled experiments with a vaporizing/burning stream of ethanol droplets.

scholarly journals Metals and Alloys Additives as Enhancer for Rocket Propulsion: A Review

2021 ◽  
Vol 90 (1) ◽  
pp. 1-9
Author(s):  
Izham Izzat Ismail ◽  
Norhuda Hidayah Nordin ◽  
Muhammad Hanafi Azami ◽  
Nur Azam Abdullah
Keyword(s):  
Specific Impulse ◽  
Flame Temperature ◽  
High Energy ◽  
Combustion Efficiency ◽  
High Energy Density ◽  
Regression Rate ◽  
High Entropy ◽  
Rocket Propulsion ◽  
Wide Range ◽  
Metal Additives

A rocket's engine usually uses fuel and oxygen as propellants to increase the rocket's projection during launch. Nowadays, metallic ingredients are commonly used in the rocket’s operation to increase its performance. Metallic ingredients have a high energy density, flame temperature, and regression rate that are important factors in the propulsion process. There is a wide range of additives have been reported so far as catalysts for rocket propulsion. The studies show that the presence of metal additives improves the regression rate, specific impulse and combustion efficiency. Herein, the common energetic additives for rocket propulsion such as metal and light metals are reviewed. Besides the effect of these energetic particles on the regression behaviors of base (hybrid) fuel has been exclusively discussed. This paper also proposed a new alloy namely high entropy alloys (HEAs) as a new energetic additive that can potentially increase the performance of the rocket propellant system.

scholarly journals IMAT-IGRT Treatment with Simultaneous Integrated Boost as Dose Escalation for Patients with Cervical Cancer: A Single Institution, Prospective Pilot Study

2021 ◽  
Vol 27 ◽  
Author(s):  
Zoltán Lőcsei ◽  
Klára Sebestyén ◽  
Zsolt Sebestyén ◽  
Eszter Fehér ◽  
Dorottya Soltész ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Total Dose ◽  
Dose Escalation ◽  
Tumor Regression ◽  
Simultaneous Integrated Boost ◽  
Disease Stage ◽  
Mri Scan ◽  
Regression Rate ◽  
Integrated Boost

Purpose: The aim of this study was to introduce the simultaneous integrated boost (SIB) technique to assess the safety of replacement of the brachytherapy (BT) boost for ineligible patients with cervical cancer receiving radiochemotherapy (RCT).Methods: Fourteen patients were enrolled between 2015 and 2018. SIB was delivered using RapidArc technique at doses of 2.4 Gy per fraction during pelvic irradiation with 50.4/1.8 Gy in seven patients (to a total dose of 67.2 Gy) with limited volume disease. In 7 patients with a more advanced disease stage (>5 cm tumor, parametric invasion both sides), parametric boost therapy was added to the pelvic radiotherapy to a total dose of the macroscopic tumor of 79.2 Gy. All patients received simultaneous cisplatin-based chemotherapy for 5 cycles with a dosage of 40 mg/m2. We examined acute toxicity (CTCAE v4.1) and quality of life (EORTC QLQ30 and CX24). The tumor regression rate was evaluated with RECIST 1.1 after the first 3- to 4-months follow-up Magnetic Resonance Imaging (MRI) scan. We calculated the percentage of tumor regression rate and the local control during the follow-up period and evaluated the survival data.Results: Our patient data are presented at a median follow-up time of 24.5 months. During the treatment period, no grade 3 to 4 toxicity was observed. During the follow-up period, no late-onset toxicity was observed. The tumor regression rate at the first MRI scan was 95.31% on average. Disease free survival (DFS) during the median follow-up of 24 months was 98.6%.Conclusion: In patients with cervical cancer, the SIB technique is amenable as part of definitive RCT. Dose escalation with the SIB technique can be safely administered to cervical cancer patients during definitive RCT if BT is not feasible. However, further randomized clinical studies are needed to validate the method, so routine use of it cannot be recommended yet.

Sign in / Sign up

Export Citation Format

Share Document