Numerical simulation of heat transfer and pressure distributions in micronozzles with surface discontinuities on the divergent contour

Sebastião, Israel B.; Santos, Wilson F. N.

doi:10.1016/j.compfluid.2013.12.023

Cited by 12 publications

(7 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…With the aid of micro-scale propulsion system, mini-spacecraft can achieve its orbit adjustment, station keeping and attitude controlling. 6–8 Micro Laval nozzle plays a significant role in micro-scale propulsion system and laser cutting system as well. 9,10 There are several different manufacturing processes for nozzle, such as etching, 11–13 electrochemical machining, 14 ultrasonic machining, 15 drilling and micro milling.…”

Section: Introductionmentioning

confidence: 99%

Optimum end milling tool path and machining parameters for micro Laval nozzle manufacturing

Cai

Liu

Shi

et al. 2015

Proceedings of the Institution of Mechanical Engineers, Part B:

View full text Add to dashboard Cite

Cutting tool path has significant effects on the performance of micro nozzles manufactured by micro machining. Different tool paths induced different directions of surface roughness. As for it, the manufacturers need to obtain optimal cutting tool path and cutting parameters. In this article, optimum machining parameters for the fabrication of micro Laval nozzle with two different end milling tool paths are presented. First, surface roughness models for different types of cutting tool paths are proposed. A case of machined nozzle surface is then given to verify the applicability of the developed roughness model. Second, theoretical profile geometries for the Laval nozzle to be manufactured are designed. Third, the influences of surface roughness on the nozzle performance parameters including total pressure, average outlet velocity and thrust are investigated through computational fluid dynamic analysis. Simulated performance parameters are contrasted with their theoretical values. It is found that for different tool paths, the nozzle of axial tool path has larger total pressure and average outlet velocity than that of circular tool path. Moreover, with surface roughness increasing, thrust decreases obviously when surface roughness Rz is larger than 4.8 μm. Micro end milling experiments based on axial tool path are then performed, and the optimum cutting parameters are obtained. Finally, a nozzle was manufactured with the axial tool path as well as the optimized cutting parameters.

show abstract

Section: Introductionmentioning

confidence: 99%

Optimum end milling tool path and machining parameters for micro Laval nozzle manufacturing

Cai

Liu

Shi

et al. 2015

Proceedings of the Institution of Mechanical Engineers, Part B:

View full text Add to dashboard Cite

show abstract

“…3 shows the micro nozzle geometry that was experimentally investigated by Hao et al [4]. This geometry was also simulated by Xie [5] and Sebastião and Santos [8,9]. The details of geometry dimensions and simulation conditions are given in Tables 2 and 3, respectively.…”

Section: Micro Nozzle Geometry and Validationmentioning

confidence: 97%

“…The sim- [4] and DSMC results of Refs. [4,8,9]. ulated micro nozzle geometry is the same as shown in Fig.…”

Section: Sbt Scheme: Grid and Ppc Independencementioning

confidence: 99%

“…Darbandi and Roohi [7] studied the effects of gas/surface interactions (diffuse/specular reflections) and Knudsen number on the flow field in micro/nanoscale nozzles. Sebastião et al [8,9] simulated arrayarranged convergent-divergent micro nozzles by using DSMC. By considering a convex-concave divergent surface, the influence of the curvature and discontinuities on the divergent surface contour is investigated for pressure, skin friction and heat transfer coefficients.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Detailed investigation of flow and thermal field in micro/nano nozzles using Simplified Bernoulli Trial (SBT) collision scheme in DSMC

Saadati

Roohi

2015

Aerospace Science and Technology

View full text Add to dashboard Cite

“…With the advent of micro-and nanosatellites in recent years, the need for the development of miniaturized propulsion devices based on Micro-Electro-Mechanical Systems (MEMS) has increased [15][16][17][18]. A MEMS-based propulsion system might consist of an array of tiny rocket thrusters on a silicon chip with electronic circuitry that controls ring.…”

Section: Introductionmentioning

confidence: 99%

Effects of geometrical parameters on the performance of a cold gas micronozzle

Heydari¹

2016

Scientia Iranica

View full text Add to dashboard Cite

The area of the exit and throat region of a nozzle play a crucial role in its design. This paper is a report of numerical simulations carried out to investigate the in uence of these parameters on the performance factors of an axisymmetric cold gas nozzle of micron-size throat diameter. It was assumed that the deviations of the ow behavior from that of a continuum ow can be taken care of by applying the rst-order slip boundary conditions at the wall. The solution methodology includes a nite-volume-based numerical procedure based on structured quadrilateral grids. A parametric study reveals that to reach the highest values of the thrust and speci c impulse, one should choose a nozzle with the highest possible throat diameter. However, by increasing the outlet diameter, the thrust initially reaches a maximum and then decreases. In these conditions, the speci c impulse is always a decreasing function of the outlet diameter of the micronozzle. It is also observed that the mass ow rate is an increasing function of both the throat and outlet diameters. In addition, the comparison of the results with and without slip velocity shows that the amounts of the mass ow rate, thrust force, and speci c impulse are higher when the rarefaction e ects are taken into account. Nevertheless, no fundamental di erence is observed in ow physics with and without slip velocity.

show abstract

Numerical simulation of heat transfer and pressure distributions in micronozzles with surface discontinuities on the divergent contour

Cited by 12 publications

References 28 publications

Optimum end milling tool path and machining parameters for micro Laval nozzle manufacturing

Optimum end milling tool path and machining parameters for micro Laval nozzle manufacturing

Detailed investigation of flow and thermal field in micro/nano nozzles using Simplified Bernoulli Trial (SBT) collision scheme in DSMC

Effects of geometrical parameters on the performance of a cold gas micronozzle

Contact Info

Product

Resources

About