Gas Flow in Nozzles

Pirumov, U. G.; Roslyakov, G. S.

doi:10.1007/978-3-642-86790-3

Cited by 50 publications

(13 citation statements)

References 5 publications

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“…The method of configurations is used as a deterministic algorithm. Its principles are described in [9]. Search for an optimum for one-dimensional gas flow yields the following optimum parameters: a = 25.97, q = 0.25, ~ = 0.0588, L = ll.7cm, x', = 0.21, (4.3)…”

Section: O~v--lk~-'l(t/-jk--v~ =mentioning

confidence: 99%

Solution of variational problems of gas dynamics with physicochemical transformations

Makarov¹

1996

J Appl Mech Tech Phys

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Section: O~v--lk~-'l(t/-jk--v~ =mentioning

confidence: 99%

Solution of variational problems of gas dynamics with physicochemical transformations

Makarov¹

1996

J Appl Mech Tech Phys

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“…In accordance with the first modification, the momentum thickness was calculated from expression (1.9) or from other similar formulas, and the specific impulse losses due to friction were then determined from relation (1.8) [6,9]. This modification was widely used for 25 years --from the latter half of the fifties up to the time at which the second, improved modification of the integral method appeared.…”

Section: Oy-oy-oymentioning

confidence: 99%

“…For a gas with a constant specific heat ratio "y equal to the value of the mean polytropic exponent of the expansion of the gas in the nozzle, the impulse losses due to dispersion, associated with the nonuniformity of the parameters in the nozzle exit section, are given by the expression [6,9] -R a…”

Section: Oy-oy-oymentioning

confidence: 99%

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Specific impulse losses due to friction and dispersion in a gas-film cooled liquid rocket engine nozzle

Лущик¹,

Sizov²,

Sternin³

et al. 1993

Fluid Dyn

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The problem of designing the best (optimum) liquid rocket engine (LRE) nozzles was formulated as early as 1931 by Glushko (see [1]).At the beginning of the fifties design offices began using parabolic or circular arc nozzle contours. The variational problem of selecting a nozzle with minimum dispersion losses was first solved in the fifties [2--5]. In [2] the solution of the variational problem was reduced to the numerical integration of a system of differential equations. In [3], independently of [2], a similar system of equations was obtained for a gas with a constant specific heat ratio and an effective means of analytic integration was found. In [4] the same integration was carried out for the generalized case of an arbitrary dependence of pressure on density. The principal result of [4] was repeated in [5]. Below, nozzles designed on the basis of [2--5] are called nozzles with a variational characteristic; they were developed in a number of design offices and used in working engines. In the American literature nozzles with a variational characteristic are called Rao nozzles after the name of the author of [5].At the Institute of Heat Processes (NIITP) in the fifties so-called tnmcated nozzle contours with a uniform characteristic were widely investigated. With respect to its thrust characteristics this one-parameter family of contours is similar to the nozzles obtained by variational methods, which is attributable to two circumstances. Firstly, for plane flows the solution of the variational problem is a truncated nozzle with a uniform characteristic. Secondly, for the axisymmetric case an untruncated nozzle with a uniform characteristic is the limiting solution of the variational problem.The investigation of the dispersion losses for both contour families has shown [6] that axisymmetric nozzles with a variational characteristic are approximately 0.1--0.2% better than truncated nozzles with a uniform characteristic. For short nozzles, as follows from calculations made at the t~nergomash NPO (1970), the difference may be much ~eater.It should be noted that although the dispersion losses, associated with the nonuniformity of the flow in the nozzle exit section, are one of the principal components of the impulse losses in the nozzle, the losses due to friction in the nozzle boundary layer are also important and usually exceed the dispersion losses.Nozzle optimization with allowance for the friction and dispersion losses in the variational formulation is an extremely complex and laborious task. One of the fast attempts was an investigation carried out by the t~nergomash NPO and the Computer Center of the USSR Academy of Sciences (1971), in which the general Lagrangian multiplier method proposed in [7] was employed. As a result of the calculations it was found that friction has only a very weak influence on the optimum contour.In the research carried out at the NI1TP [6] using direct calculation methods, without solving the variational problem, it was shown that the optimum contours having minimum friction and d...

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“…In the field of the fluid flow in nozzles, there are many basic and specialized literature [1][2][3]. This issue is deeply investigated and continuously broaden out till present.…”

Section: Introductionmentioning

confidence: 99%

Pressure and velocity conditions in home health care accessory for babies

2018

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The home health care accessory for babies is selected for investigation. The objectives are to find out the maximal under-pressure and air velocity, which is possible to reach by accessory Nosko® using standard home vacuum cleaner recommended by manufacturer of the accessory. CFD software is used for prediction of the flow characteristics of the air in the body of the accessory. Also simple experiment with the trace is performed in the transparent body. The flow characteristic of the Nosko® is obtained by systematic simulation and can be used for further engineering calculation and detailed investigation. Maximum flow rate of the air through the accessory under maximal under pressure generated by home vacuum cleaner was 2.6 litres. s-1 which is comparable with results of investigation of the human breathing in the literature source.

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Gas Flow in Nozzles

Cited by 50 publications

References 5 publications

Solution of variational problems of gas dynamics with physicochemical transformations

Solution of variational problems of gas dynamics with physicochemical transformations

Specific impulse losses due to friction and dispersion in a gas-film cooled liquid rocket engine nozzle

Pressure and velocity conditions in home health care accessory for babies

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