Papers by Keyword: Nozzle Design

Abstract: A computational method for the steady 2-D flow in axially symmetrical rocket nozzles with a given profile is developed, in order to determine the Maximum thrust contour of rocket engine nozzles with large expansion ratio. The optimized nozzles proved a more than 10% increase in the integral specific impulse recorded during the variable altitude atmospheric flight of rocket vehicles. The method is well suited for application in the design of the optimum contour for axially-symmetric nozzles for atmospheric rocket ascent, specifically for aerospike type nozzles, as for other similar industrial applications in gas and steam turbine technology.

Abstract: For the intake restrictors which are designed in line with FSAE race stipulations, this paper carries out compute simulation on the convergent section and divergent section of the intake restrictors via CFD software; the paper systemically analyzes the distribution characters of its flow field, thus obtaining optimal design scheme. It finds through simulation that: when the converging half angle of the restrictor is less than 45°, the outlet flow of the restrictor will decrease as the converging half angle increases; meanwhile, the divergence half angle will affect the outlet flow of the restrictor as the pressure difference between the restrictor inlet and outlet varies. According to the simulation results, the optimal scheme finally designed is: the intake restrictor has the best effect when the converging half angle of the restrictor is 10°, while the divergence half angle is 11°.

Abstract: The jet propulsion system, either for subsonic or supersonic flow, the nozzle design is a critical area of choice where its overall performance gets an adverse change. In the trending technologies, configuring any nozzle, their challenges associated with the design increases accordingly to the cruise speed of the aircraft. The latter clamshell ejector nozzle design work came up with solution for the most problems but still had its own cons of creating recirculation zone in the inner surface of the clamshells. The former world which are in next stage to design an economically conditioned nozzle system itself invents challenges in area such as jet noise suppression, exit temperature, material selection, variable throat area and exit area. The present work summarized here excelled for the most cons encountered in the latter designs. The experimental investigation and the computational studies resulted that the introduction of C-D nozzle with by-pass system had a great exposure in increasing the Mach while in cruise. The air by-pass system in the exit area supplies the atmospheric air and also acts as a cooling system for the nozzle. It was observed that the temperature curve in the exit area was found low.

Abstract: In order to meet the need of production and promote the smelting efficiency of converter, Pangang Vanadium-extracting&Steel Making Plant optimized oxygen lance nozzle according to the situation of primary 120t converter semi-steel making and have inspected new oxygen lances smelting effect in industrial test. The test shows that the average oxygen blowing intensity raised 0.19m³/t·min with optimized nozzle, shortened oxygen blowing time by 56s,total iron in final slag reduced 0.7%, dephosphorizing rate rose to 82.10% from 79.06%, which developed a good result.

Abstract: The Pneumatic atomizing nozzle is quenching test professional nozzle which is designed for new quenching process taking high-pressure nitrogen gas water as quenching medium. It meets the requirements of high pressure nitrogen quenching process and reaches the requirements that particle size can be adjusted, flow spray field coverage angle is large, flow and pressure are adjustable and the amplitude of accommodation is big. The nozzle special for high-pressure gas quenching test is less and it can only be chose from other functional nozzles, having great limitations. The development of nozzle special for high-pressure gas quenching will have a certain role in promoting the popularization of high-pressure gas quenching technology and the development of nozzle technology.

Abstract: Cold spray (CS) is an emerging revolutionary technology for deposition of metal or composite powders at a low temperature. High quality deposits can be produced without heating related defects, such as oxidation, phase transformation and residual tensile stress due to the shrinkage during fast cooling. The present contribution demonstrates the state of the art of CS process. Since nozzle is a key component in the CS equipment to prompt the efficiency of particle acceleration, the progress of its design is summarized. Major issues regarding to the successful adhesion of particles and corresponding interaction with substrates and existing deposits are discussed, in terms of numerical simulation and experimental observation. Current implemented CS applications are presented, and potential industrial applications are discussed. Keywords: cold spray; coatings; rapid manufacturing; particle impact; bonding mechanism; nozzle design

Abstract: In the oil and gas production process, serious sand production causes reservoir and pipe blocked, which makes productivity declined, even stopped. It's the efficient means of sand washing and plug removal by using high-pressure foam fluid jet. The structure and performance of sand washing device determines the efficiency of sand washing and plug removal. The device's nozzle consists of anti-blocking valves, three kinds of nozzles with self-drive, rotation characteristics during the operation. The nozzles include sand washing nozzle, couple nozzle and power nozzle. This device can be used in horizontal wells with complex well bore situation to carry out sand and plug removal. The device has a good effect on sand washing and plug removal in the oil field.

Abstract: The most important parameter for production of fine powders efficiently is the velocity of the atomizing gas. This can be achieved by increasing the pressure, but this way will not be economic. For that reason, to achieve supersonic velocities different nozzle designs are used in close coupled configuration for an efficient atomization. In this study, a new laval type nozzle was designed and manufactured. Using this nozzle tin powder was produced in close coupled system by using nitrogen gas at different operating conditions. The results showed that the increasing the gas pressure up to 1.47 MPa reduced the mean powder size down to 11.39 microns with a gas/melt mass flow rate ratio of 2.0. Powders are spherical in shape and have smooth surfaces.

Abstract: The cold spray process is a relatively new process using high velocity metallic particles for surface modifications. Metallic powder particles which are injected into a converging-diverging nozzle are accelerated to supersonic velocities. In this study effects of nozzle design such as diameter of nozzle throat and length of converging and diverging part of the nozzle on gas and particle velocities developed after the nozzle exit are investigated.

Abstract: In Cold Spray method, a coating is formed by exposing a substrate to high velocity solid-phase particles, which have been accelerated by supersonic gas flow at a temperature much lower than the melting or softening temperature of the feedstock. Therefore, the nozzle geometry is important with regard to the cold spray method. This Cold Spray process is an exciting new spray technology that has the potential to overcome limitations of more traditional thermal spray processes for some important commercial applications. With this emerging technology, it is possible for the first time to rapidly deposit thin or very thick layers (mm to cm+) of a wide range of metals, and even some composite materials, without melting or vaporization, at or near room temperature, in an ambient air environment. Some potential areas of interest include:  corrosion protection,  wear reduction, highly conductive coatings (electrical or thermal), metal/glass or metal/ceramic joints (with less residual stress), ceramic/metal or graded metal/metal composites,  thick deposits (mm to several cm range), reclamation of worn or mis-machined parts, metallization of glass or ceramics. The applications of Cold Spray can be examined in the field of an automobile and a rocket engine.