scholarly journals Hybrid Rocket Underwater Propulsion: A Preliminary Assessment

Aerospace ◽  
2019 ◽  
Vol 6 (3) ◽  
pp. 28 ◽  
Author(s):  
Heejang Moon ◽  
Seongjoo Han ◽  
Youngjun You ◽  
Minchan Kwon
Keyword(s):  
Nozzle Exit ◽  
Propulsion System ◽  
Test Case ◽  
Test Bed ◽  
Hybrid Rocket ◽  
Preliminary Assessment ◽  
Soft Start ◽  
Rupture Disc ◽  
Underwater Propulsion ◽  
Hybrid Motor

This paper presents an attempt to use the hybrid rocket for marine applications with a 500 N class hybrid motor. A 5-port high density polyethylene (HDPE) fuel grain was used as a test-bed for the preliminary assessment of the underwater boosting device. A rupture disc preset to burst at a given pressure was attached to the nozzle exit to prevent water intrusion where a careful hot-firing sequence was unconditionally required to avoid the wet environment within the chamber. The average thrust level around 450 N was delivered by both a ground test and an underwater test using a water-proof load cell. However, it was found that instantaneous underwater thrusts were prone to vibration, which was due in part to the wake structure downstream of the nozzle exit. Distinctive ignition curves depending on the rupture disc bursting pressure and oxidizer mass flow rate were also investigated. To assess the soft-start capability of the hybrid motor, the minimum power thrust, viewed as the idle test case, was evaluated by modulating the flow controlling valve. It was found that an optimum valve angle, delivering 16.3% of the full throttle test case, sustained the minimum thrust level. This preliminary study suggests that the throttable hybrid propulsion system can be a justifiable candidate for a short-duration, high-speed marine boosting system as an alternative to the solid underwater propulsion system.

scholarly journals Hybrid Propulsion System: Novel Propellant Design for Mars Ascent Vehicles

2021 ◽  
Author(s):  
Ozan Kara ◽  
Arif Karabeyoglu
Keyword(s):  
Low Cost ◽  
Flame Temperature ◽  
Propulsion System ◽  
Hybrid Rocket ◽  
General Audience ◽  
Hybrid Propulsion ◽  
Test Setup ◽  
Rocket Propulsion ◽  
Hybrid Motor

This chapter briefly introduces hybrid rocket propulsion for general audience. Advantageous of hybrid rockets over solids and liquids are presented. This chapter also explains how to design a test setup for hybrid motor firings. Hybrid propulsion provides sustainable, safe and low cost systems for space missions. Therefore, this chapter proposes hybrid propulsion system for Mars Ascent Vehicles. Paraffin wax is the fuel of the rocket. Propulsion system uses CO2/N2O mixture as the oxidizer. The goal is to understand the ignition capability of the CO2 as an in-situ oxidizer on Mars. CO2 is known as major combustion product in the nature. However, it can only burn with metallic powders. Thus, metallic additives are added in the fuel grain. Results show that CO2 increase slows down the chemical kinetics thus reduces the adiabatic flame temperature. Maximum flammability limit is achieved at 75% CO2 by mass in the oxidizer mixture. Flame temperature is 1700 K at 75% CO2. Ignition quenches below the 1700 K.

Multiscale Partially Averaged Navier Stokes Approach for the Prediction of Flow in Linear Compressor Cascade With Moving Casing

2011 ◽  
Author(s):  
Domenico Borello ◽  
Giovanni Delibra ◽  
Franco Rispoli
Keyword(s):  
Turbulence Models ◽  
Navier Stokes ◽  
Test Case ◽  
Compressor Cascade ◽  
Preliminary Assessment ◽  
Linear Compressor ◽  
Tip Leakage ◽  
Experimental Campaign ◽  
Elliptic Relaxation ◽  
Linear Compressor Cascade

In this paper we present an innovative Partially Averaged Navier Stokes (PANS) approach for the simulation of turbomachinery flows. The elliptic relaxation k-ε-ζ-f model was used as baseline Unsteady Reynolds Averaged Navier Stokes (URANS) model for the derivation of the PANS formulation. The well established T-FlowS unstructured finite volume in-house code was used for the computations. A preliminary assessment of the developed formulation was carried out on a 2D hill flow that represents a very demanding test case for turbulence models. The turbomachinery flow here investigated reproduces the experimental campaign carried out at Virginia Tech on a linear compressor cascade with tip leakage. Their measurements were used for comparisons with numerical results. The predictive capabilities of the model were assessed through the analysis of the flow field. Then an investigation of the blade passage, where experiments were not available, was carried out to detect the main loss sources.

A Web-Accessible Robotics Monitoring System Powered by a Thermoelectric Generator Connected to a Battery

2014 ◽  
Author(s):  
Robert Dell ◽  
Runar Unnthorsson ◽  
C. S. Wei ◽  
William Foley
Keyword(s):  
Peak Power ◽  
Thermoelectric Generator ◽  
Small Scale ◽  
Test Case ◽  
Test Bed ◽  
Robot System ◽  
Source Power ◽  
Power Generator ◽  
The Stability ◽  
Electrical Supply

In small source power generation scenarios in industrial or remote settings a viable small electrical supply for security and monitoring systems is often problematic due to the variability of the energy sources and the stability of the power generated. These small scale systems lack the advantages of a larger power grid. Therefore peak power requirements can be beyond the power generator necessitating energy storage such as batteries. The authors have developed and documented a reliable thermoelectric generator and a test bed. The generator was combined with a battery in order to meet peak power requirements beyond the unassisted range of the generator. This paper presents a test case result with the thermoelectric generator powering a complete web accessible mobile robot system. The robot system can be used for monitoring, physical manipulation of the environment, routine maintenance and in emergencies.

Development and testing of an efficient and cost-effective underwater propulsion system

2019 ◽  
Vol 233 (10) ◽  
pp. 1309-1328
Author(s):  
Libero Paolucci ◽  
Emanuele Grasso ◽  
Francesco Grasso ◽  
Niklas König ◽  
Marco Pagliai ◽  
...  
Keyword(s):  
Permanent Magnet ◽  
High Efficiency ◽  
High Reliability ◽  
Underwater Vehicle ◽  
Propulsion System ◽  
Permanent Magnet Synchronous Motors ◽  
Synchronous Motors ◽  
Vehicle Propulsion ◽  
Underwater Propulsion ◽  
Thrust And Torque

Underwater vehicle propulsion performed by exploiting electrical motor is in general the most flexible solution and it is growing in popularity because of its high efficiency both at high and at low advance speed, quick and simple deployment, low costs, and encumbrance. In the present work, permanent magnet synchronous motors for underwater propulsion are proposed. In particular, advanced sensorless control techniques of permanent magnet synchronous motors permit reduced costs, high reliability, and performances. When dealing with small autonomous underwater vehicle propulsion, such devices are hard to find in the market. Hence, the authors focused the research in the development of a system able to perform a reliable rotational speed and torque sensorless estimation. The design and implementation of a complete solution for underwater propulsion are presented as well as a novel rotor polarity identification technique exploiting a high-frequency injection control. Pool tests for the identification of the performances and of the dynamic parameters of the propulsion system are presented. Finally, the possibility of operating a sensorless estimation of the thrust and torque exerted by the propeller and pool test measurements are presented. These features could be exploited to improve navigation accuracy and involves obvious benefits in terms of cost reduction and reliability of the system.

Modeling and Simulation of Marine Diesel Propulsion System in Ship Maneuvering Condition

2011 ◽  
Vol 354-355 ◽  
pp. 472-477 ◽  
Author(s):  
Hai Yan Wang ◽  
Hui Yan Tang ◽  
Jian Hui Sun
Keyword(s):  
Simulation Models ◽  
Propulsion System ◽  
Longitudinal Motion ◽  
Test Bed ◽  
Bulk Carrier ◽  
Ship Maneuvering ◽  
Sea Trial ◽  
Good Accordance ◽  
Marine Diesel ◽  
Stop Condition

To study all-regime performance of marine diesel propulsion system in ship maneuvering, an all-regime model for diesel propulsion system is established, including starting, braking, reversing, etc. The dynamic simulation models of propeller running across four quadrants and ship longitudinal motion are given too. A 76000DWT bulk carrier is selected as plant. The simulation results show that steady data of diesel are in good accordance with test-bed data, and dynamic data match to ship sea trial data in crash stop condition. The model is accurate and effective.

Design of a Small Scale Gas Turbine for a Hybrid Propulsion System

2015 ◽  
Author(s):  
Elliott Bryner ◽  
David Ransom ◽  
John Bishop ◽  
Shane Coogan ◽  
Grant Musgrove
Keyword(s):  
Gas Turbine ◽  
New Technologies ◽  
Low Cost ◽  
Lessons Learned ◽  
Propulsion System ◽  
Small Scale ◽  
Test Bed ◽  
Gas Generator ◽  
Original Design ◽  
Hybrid Propulsion

As part of the Great Horned Owl (GHO) program Southwest Research Institute© (SwRI©) has developed a small, lightweight gas-turbine generator to provide power for an electric or hybrid electric Unmanned Aerial Vehicle (UAV). This original design for a fuel-to-electricity component of a hybrid propulsion system was designed, built and tested at the SwRI facility in San Antonio, TX. The design is based on a patented SwRI gas-turbine configuration and went through five major design iterations leading to the final configuration. The design iterations of the gas generator were driven by aggressive targets for weight, size and performance that were part of program requirements. The design of the GHO machine evolved from the initial concept based on lessons learned from previous testing at SwRI and considerations to improve manufacturability and operability. Improvements to the design were also incorporated to meet performance goals and increase life of hot section parts. This machine is low-cost and simple to operate and in addition to the original design intent of fuel-to-electricity use in a hybrid propulsion system can be used as a technology demonstration platform. SwRI plans to use the GHO machine in projects such as instrumentation development, as a test bed for new technologies such as ceramic or additive manufactured parts and for use as a component in a hardware-in-the-loop system.

Hydropulse underwater propulsion system

1983 ◽  
Vol 73 (3) ◽  
pp. 1089-1089
Author(s):  
Allen C. Hagelberg ◽  
Clark E. Allardt
Keyword(s):  
Propulsion System ◽  
Underwater Propulsion
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