이중공기공급 속도비에 따른 이류체 선회분무 특성 연구

노병준,강신재,오제하,송기정 한국액체미립화학회 2000 한국액체미립화학회지 Vol.5 No.3

In this study, spray characteristics of a dual airblast atomizer are addressed. Three dimensional characteristics of a dual airblast atomizer with air swirl are measured to Provide the significant data The liquid flow rate was fixed at 0.06 kg/min, and atomizing air was controlled at the liquid-air mass ratio of 4.0. The performance of the spray with co-swirl and counter-swirl flow was investigated at each point in the developed spray region using a Un~e-component phase Doppler particle analyzer. This instrument was also used to evaluate the concentration profiles. The three dimensional mean velocity were investigated to present flow characteristics of the dual airblast atomizer. 1n addition, drop size distributions, mean droplet size profile, and droplet concentration were analyzed to understand atomization characteristics. This experimental results can be conveniently utilized for the preliminary design of gas turbine engines for aircraft.

熱線風速計에 依한 陰速度 領域 解析에 關한 硏究 : 半徑方向 空氣 Jet 에서 For air Jet in the Radial direction

盧秉俊 전북대학교 공업기술연구소 1981 工學硏究 Vol.11 No.-

For the analysis of the megative velocity region by hot-wire anemometer, a valve jet systiem, as a experimental set-up, equiped at the outlet of the sub-sonic wind tunnel was used. To effectuate this study, an experimental system(valve jet) which could develop a jet flow inducing a secondary one(i.e.:inverse flow or entrained flow) was designed and fabricated. With a hot-wire anemometer system, the mean veolcity values in the radial direction across the jet have been measured at the various point in the axial direction of the valve, where the valve opening and the radial distance were fixed for each measurement(b-9㎜, r=50, 60, 70㎜). By derivation of the flow angle graphically by means of the topographical method, the data obtained have been evaluated by the formula U­cosα, which derives the velocity profile including the positive and the negative velocity regions, and from which one could analyse the actual flow phenomenon and their values. By putting the factors at the maximum velocity region as a non-dimensional function, a similitude equation was derived graphically and its results were analysed.

두 四角 Nozzle에 의한 Crosss Jet에서 Reynolds 應力 分布 特性에 關한 實驗的 硏究

盧秉俊,鄭材鍊 전북대학교 공업기술연구소 1983 工學硏究 Vol.14 No.-

For the experimental study on the Reynolds stress distribution in the cross jet flow, two rectangular nozzles with same dimensions were used. Mean velocities, Reynolds stresses and correlation coefficients were measured and analysied at the mixing region of 45℃-crossed jets. These results were obtained as follows. 1) The mean velocity distributions in the axial direction were agreed with the empirical equation of G^'˙˙tler except for 0<Y/b<0.5 at X/Xc=0.93-1.0, and were apparently different from that of y-direction whose maximum velocity Vmax was about 6% of the axial one U^­max. 2) The maximum intensity of turbulence for x-direction varies from 24% to 27% at Y/b=1, for y-direction its variation ws 25%-27% at Y/b=0.2. 3) The variance of x, y-direction, (u'^2)￣/U^￣max and (v'^2)￣/U^￣max was 0.06 and the covariance (u'v')￣/U^￣max was 0.018. Their values were obtained at Y/b=0.4, 1.0. 4) The distribution of correlation coefficients was Ru'v'=0.5~0.4 for Re, NO. 4.62^* and Ru'v'=-0.9~0.4 for Re, NO. 9.24^* 10^4.

Cross Jet 에서 Reynolds No. 變化에 따른 亂流成分 分布에 關한 實驗的 硏究

盧秉俊,鄭材鍊 전북대학교 공업기술연구소 1983 工學硏究 Vol.14 No.-

In order to effectuate an experimental study on the distribution of Reynolds, stresses. a cross jet kit with two rectangular nozzles was mounted at the outlet of a subsonic windtunnel. The mean and fluctuating velocities and Reynolds stresses were measured at some particular points according to the variation of Reynolds No. The mean velocities in the Y and Z-direction and the fluctuating velocities in the three dimensional directions increase lineary as the Reynolds No. increases. The variances (U￣′^2, V￣ ′^2, w￣′^2) and covariances (u￣′v′, u￣′w′ ) show the increasing phenomenon with the increasement of Reynolds No. and their order of magnitude was v￣′^2>u￣′^2>w￣′^2 in the fully developed turbulent flow region of the cross jet.

吸入밸브를 利用한 半徑 方向 亂流 噴射 流動에 관한 硏究

盧秉俊,尹錫柱,梁在鉉,姜信再 전북대학교 공업기술연구소 1987 工學硏究 Vol.18 No.-

Cross Jet의 亂流流動에 對한 實驗的 考察 : 2nd Report: for the structure of two cross jet flows

盧秉俊 全北大學校 1983 論文集 Vol.25 No.-

This experimental study was effectuated as second investigation on the cross jet using a circular section nozzle. The measurement and the analysis of the cross jet flows in the axial direction give following results. (1) Visualization shows that the 45°cross jet flows exactly to the axial direction and it represented an axisymmetric velocity distribution profile. The structure of the complete mixed flow region was appeared like a singe jet flow. (2) The increase of the vertical width of the mixed flow was larger than the horizontal one. The momentum flow rate and the inertia force developed by the jet flows oriented to 22.5° caused a little increase of the horizontal width of the jet section. The minimum width of the mixed flow section existed at X/X_0=1.30. (3) The intensity of turbulence was axisymmetrically distributed and its profile was shown as a singe jet. (4) The velocity of the mixed flow along the centerline increases linearly before X/d??12, but it abruptly decreases in the region of 12<X/d<20 and it slowly decrease after X/d=20. The maximum velocity was formed at X/X_0=1.07∼1.12 independent upon the variation of the velocity. (5) The momentum variation showed a little decrease according to the increase of the axial distance because of the gradient of the back pressure from cross jet flow and the decay of the mean velocity caused by the increase of turbulence.

粒體의 空氣輸送에서 管路閉塞에 關한 硏究

盧秉俊 전북대학교 공업기술연구소 1975 工學硏究 Vol.4 No.-

The condition, in pneumatic conveyance of granular solids, that is impossible to convey has been experimented with emphasis on the blockade of pipe line in case of low pneumatic conveyance velocity. The blockade has various factors, of them the pneumatic conveyance velocity and supply quantity of granular solids are regarded as the most important ones. And then, on the base of that, this has been experimented and examined. According to the results, the positions of the blockade point have been changed depending upon the variation of Fr. No. and the ratio of mixture. So it is believed that, as the specific weight is in the range of 1.23 g/㎤-1.44 g/㎤ and the supply quantity of testing materials has 40 g/sec.-80 g/sec. ranges. the limit of Fr. No. (limit velocity) is as follow.

액막형 동축노즐의 2상 난류분사의 미립화 특성에 관한 실험적 연구

노병준,강신재,오제하 대한기계학회 1995 대한기계학회논문집 Vol.19 No.6

In this study, a liquid sheet type co-axial nozzle has been used to investigate the turbulent atomization characteristics which could result in the experimental data to be used in designing a jet nozzle with high performance. Image processing technique and immersion sampling method were employed to measure droplet size. In atomizing characteristics, droplet size distributions and absolute droplet sizes, SMD(Sauter Mean Diameter) have been investigated in the wide ranges of flow field depending upon the air-water mass ratios. And the comparisons between the present data and the semi-empirical curves have been conducted semi-empirical correlation for SMD has been derived in the present analysis.

Cylinder 內 교차분사의 亂流混合流動에 對한 統計學的 亂流特性 考察

盧秉俊,趙元日,梁在鉉 전북대학교 공업기술연구소 1985 工學硏究 Vol.16 No.-

For the study on the cross jet flow in the cylinder, cross jet kit with two circular nozzles(exit diameter ∅20) was mounted at the exit of the subsonic wind tunnel. the geometrical cross point of the centerline of two nozzles exists at 120.7㎜ from the exit of the nozzle in the downstream of the mixed flow, so the developing turbulent mixing region could be imagined to exist in the excess of the point. The distributions of the one dimensional probability density, flatness factor, skewness factor and joint probability density were measured and analysed at that region using hot-wire anemometer and on-line data processing computer system.

V-形 Slit 噴射에 對한 實驗的 考察

盧秉俊,鄭材鍊,姜永準 전북대학교 공업기술연구소 1983 工學硏究 Vol.13 No.-

In this report, a free axisymmetric turbulent jet issuing from V-shaped slit(with an angle 30˚) in the axial direction has been studied. The structure of the flow behind the full mixed flow region show a single free jet velocity distribution profiles. Comparing the mean velocity distribution profiles with those calculated by the empirical equation of H. Schilichtin and Abramovich. They coincide well in the region of Ū/Ū_max ≧ 0.2, but they almost become a constant value at the region of Ū/Ū_max < 0.2. the velocity variation was examined along center line, after X/a=21, this mean velocity distribution decreases linearly. The distribution of fluctuating velocity and the intensity of turbulence also symmetrically distributed along the center line, and according to the Z the values are apparently varied in the central part but not in the outer sides. Finally behind the full mixed flow region, the distribution profiles represent a very classical single jet form.