Problems a nd effects of stabili zing co mb ustion and detonation again st hyp erso nic flow were investigatcd by obser vation of a. 20 millimeter sphe ri cal missile in a stoichiometric mixture of hydroge n a nd a ir at rest. Co n'lbustio n produ ced d etectable effects on t he shap e a nd posit ion of t he shock wave at M ac h n umbers between 4 and 6.5, a nd a bove press ure:> o f one-ten th at mosphere. Chemical equilibrium p robabl y was no t reached i n t he t i me t he gas spent near t he front o f t he sphere. One o f t he facto rs i n t he delayed equ ilibr iu m was d elayed igni tion behind t he s hock wave, which was observed to be between a bou t one a nd tell microseco nds. Igni t ion delay is ex plain ed in terms of chemi cal kin etic t heory and co mpared wi t h resul ts of experim ents in shoc k t ubes. Strong co mbustio n-driven oscill at ions ori ginated in fro nt o f t he s phe re, with frequ e ncies u p to a bo ut one-te nt ll m egacycle per second . These were observed wh en t he Yr ac h Jlulnber was less t llan 6 at a pressure of oneh a lf at mosphere, a nd less t han 5 at one-qu a rte r atmos phere. A la rge redu ction of t he draO' coe ffi cient o f t he mi ssile was noted in one case of inter mitte nt com bustion.
The bell prover is widely used for gas flowrate measurements by timing a known stroke of the bell as it rises, presumably with a constant speed, from a bath of sealing liquid. A differential equation for the bell motion (from the previous paper of the same title) is used together with the previous equations of motion for the gas and sealing liquid modified here to provide the basis for a computer simulation of the prover performance. Examples of the results of the computations show substantial fluctuations in all of the motions and modified measurement procedures for improved accuracy are discussed. Proposed modifications to the prover itself are shown by the computations to dampen the fluctuations and to improve the measurement accuracy. Only a limited number of changes of the prover design and of the initial conditions were researched for their effect.
A st udy of sa mpling of hoL co mbustion gases b y means of wate r-coo led probes o f i n Lc rn ed diam eter of 0.027 to 0.070 cm has been m acl e. E ffect of co ndiLio ns of s amp li n~ on conccntrat lOn s o f CO, CO" H " a ncl H 20 ,,"as Lhe primary interesL in Lhi s sL udv. The probe'S wcr c unabl e to q ueneh r eaction s eompletel .v ancl .wel ."e u nable to prese r ve the orig i nal compositio ll of t he gas, b u t sm all prob es wcr e more efi ectl ve than larger probes. Sampl e composiLion was unaffected by sa mplll1g. veloClt.v, exce pt t h at at the hi g her rates of sampli ng it appears t h at grad ien t s o f compO SILlO n and tc mperature ea used the effectiveness of qu enchil'" Lo decr ease. Pro be m ate r ial a nd co nfiguratio n had li ttle effect on s>, mplc composi tion.b
Calibration techniques for liquid flowmeters are discussed with emphasis on problems which are known to influence the accuracy of calibration procedures. Also, reference methods which have been used to evaluate the comparative accuracy of different calibrators are described. The results of comparative accuracy tests on four calibrators of different designs are presented and it is shown that the agreement between these is within ±0.15 per cent in the test range of 10,000 to 100,000 lb per hr. The many precautions necessary to approach this precision from the traditionally accepted “plus and minus one per cent” are given in detail.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.