The Acoustic Performance of 3D Printed Multiple Jet Nozzles with DifferentConfigurations

This work investigated multiple jet nozzles with various geometrical shape,number of exits,and material on reducing noise radiated from jet flows.Nozzles are categorized in two groups with few and many exit numbers,each with various exit shapes,slot and circular,and geometry.Firstly,nozzles are designed and then fabricated by a 3D printer,Form Labs,Form2USA,with polymeric resin.Also,the nozzle with the most noise reduction made of stainless steel.Noise and air thrust were measured at three air pressure gauges,3,5,7 BAR and directions from nozzle apex,30°,90°,135°.Nozzles with slot exit shape made of both plastic and stainless steel revealed the most noise reduction among all nozzles with few exit numbers,nearly 11–14 dB(A)and 11.5–15 dB(A),respectively.On average,slotted nozzle noise reduction was nearly 5–6 dB(A)more than finned nozzle.However,nozzles with more exit numbers,finned and finned-central exit,illustrated much more noise reduction than nozzles with few exit numbers,by almost 16–18 dB(A),they represented similar sound.All tested nozzles and open pipe demonstrated equal air thrust at each pressure gauges.The nozzles with slotted exit shape,either plastic or stainless steel,can provide reasonable noise reduction in comparison to other configuration with few exit numbers.In contrast,nozzles with more exit numbers demonstrated the most noise reduction.

Reducing Occupational Noise Propagated from Centrifugal Fan through Dissipative Silencers:A Field Study

Acoustic performance of dissipative silencer was evaluated to determine the effectiveness of perforated duct porosity and absorbent material density in reducing occupational noise exposure propagated from centrifugal fan.Design charts were applied to predict noise reduction and length of a dissipative silencer.Dissipative silencers with various punched duct porosity(14%,30%and 40%)and sound absorbent density(80 Kg/m^(3),120 Kg/m^(3),and 140 Kg/m^(3))were designed and fabricated.According to ISO9612 and ISO11820,noise level was measured before and after installing all nine test silencers at fixed workstations around the discharge side of a centrifugal fan in a manufacturing plant.On average,the noise level at the discharge side of a fan without silencer was measured to be 93.6 dBA,whereas it was significantly mitigated by 67.4 dBA to 70.1 dBA after installing all silencers.Dynamic insertion loss for a dissipative silencer with 100 cm length was predicted to be 27.9 dB,which was in agreement with experimental ones.Although,there was no significant differences between insertion loss of silencers,the one with 30%porosity and 120 Kg/m^(3)rock wool density had the highest insertion loss of 26.2 dBA.Dissipative silencers noticeably reduced centrifugal fan noise exposures.Increasing sound absorbent density and duct porosity up to a certain limit could probably be effective in noise reduction of dissipative silencers.

Experimental investigation of wettability alteration on residual oil saturation using nonionic surfactants: Capillary pressure measurement

Introducing the novel technique for enhancing oil recovery from available petroleum reservoirs is one of the important issues in future energy demands.Among of all operative factors,wettability may be the foremost parameter affecting residual oil saturation in all stage of oil recovery.Although wettability alteration is one of the methods which enhance oil recovery from the petroleum reservoir.Recently,the studies which focused on this subject were more than the past and many contributions have been made on this area.The main objective of the current study is experimentally investigation of the two nonionic surfactants effects on altering wettability of reservoir rocks.Purpose of this work is to change the wettability to preferentially the water-wet condition.Also reducing the residual oil saturation(Sor)is the other purpose of this work.The wettability alteration of reservoir rock is measured by two main quantitative methods namely contact angle and the USBM methods.Results of this study showed that surfactant flooding is more effective in oil-wet rocks to change their wettability and consequently reducing Sor to a low value.Cedar(Zizyphus Spina Christi)is low priced,absolutely natural,and abundantly accessible in the Middle East and Central Asia.Based on the results,this material can be used as a chemical surfactant in field for enhancing oil recovery.

Estimation of water saturation by using radial based function artificial neural network in carbonate reservoir:A case study in Sarvak formation

Water saturation determination in core laboratory is known as a cost and time consuming labor.Hitherto,many scientists attempted to estimate accurately water saturation from well-logging data which has a continuous record without losing information.Therefore,various model were introduced to relate reservoir properties and water saturation.Since carbonate reservoir is very heterogeneous in shape and size of pore throat,the relation between water saturation and other carbonates reservoir properties is very complex,and causes considerable overall errors in water saturation calculation.By increasing the usage and improvement of soft computing methods in engineering problems,petroleum engineers have been attended them to measure the petrophysical properties of the reservoir.In this study,a radial basis function neural network(RBFNN)improved by genetic algorithm has been employed to estimate formation water saturation by using conventional well-logging data.The used logging and core data have been gathered from a carbonated formation from one of oilfield located in south-west Iran,and finally their results of the proposed model were compared with the core analysis results.By checking the testing data from another well,it showed this method had a 0.027 for mean square errors and its correlation coefficient is equal to 0.870.These results implied on high accuracy of this model for oil saturation degree estimation.While the common methods like Archie,had a 0.041 mean square error and 0.720 of the correlation coefficient,which indicate a high ability of RBF model than the other usual empirical methods.