Numerical and Experimental Investigation of the Acoustic and Flow Performance of Intake Systems

2002 ◽  
Vol 124 (3) ◽  
pp. 334-339 ◽  
Author(s):  
P. A. Rusch ◽  
A. K. Dhingra

This paper investigates the acoustic and flow performance of an intake system using numerical and experimental techniques. The acoustic and flow performances are characterized by computing the Insertion Loss (IL) and the loss coefficient (LC) respectively. An indirect BEM formulation is used to predict the IL. The LC is computed by solving a one-dimensional fluid dynamics problem. For four simple cylindrical duct systems, numerical results for IL and LC are compared with experimental measurements. Finally, the acoustic and flow performance of an actual motorcycle intake is predicted and the results are compared to bench test results.

2021 ◽  
Vol 263 (5) ◽  
pp. 1548-1554
Author(s):  
Kevin Herreman

Reducing industrial noise emission utilizing jacketed pipe insulation is critical to reducing noise in industrial spaces. The ISO 15665 standard defines a testing process for measurement of the acoustical performance of installed and jacketed pipe insulation systems. However, the cost of testing per this standard, especially when using an external laboratory, can be very costly. That makes the development of a model to accurately estimate the performance of single, and multilayered, jacketed pipe insulation highly desirable. Utilizing a one-dimensional theoretical acoustic model along with empirical data, a model with sufficient accuracy to provide insertion loss results relative to the ISO 15665 standard was created. The creation and resulting functionality of the model for determining jacketed pipe insulation insertion loss and comparison of the resulting data to test results will be discussed herein.


Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 229
Author(s):  
Siva Avudaiappan ◽  
Erick I. Saavedra Flores ◽  
Gerardo Araya-Letelier ◽  
Walter Jonathan Thomas ◽  
Sudharshan N. Raman ◽  
...  

An experimental investigation is performed on various cold-formed profiled sheets to study the connection behavior of composite deck slab actions using bolted shear connectors. Various profiles like dovetailed (or) re-entrant profiles, rectangular profiles and trapezoidal profiles are used in the present investigation. This experimental investigation deals with the evaluation of various parameters such as the ultimate load carrying capacity versus deflection, load versus slip, ductility ratio, strain energy and modes of failure in composite slab specimens with varying profiles. From the test results the performance of dovetailed profiled composite slabs’ resistance is significantly higher than the other two profiled composite deck slabs.


Author(s):  
Manoochehr Darvish ◽  
Bastian Tietjen ◽  
Daniel Beck ◽  
Stefan Frank

The main focus of this work is on the geometrical modifications that can be applied to the fan wheel and the volute tongue of a radial fan to reduce the tonal noise. The experimental measurements are performed by using the in-duct method in accordance with ISO 5136. In addition to the experimental measurements, CFD (Computational Fluid Dynamics) and CAA (Computational Aeroacoustics) simulations are carried out to investigate the effects of different modifications on the noise and performance of the fan. It is shown that by modifying the blade outlet angle, the tonal noise of the fan can be reduced without affecting the performance of the fan. Moreover, it is indicated that increasing the number of blades leads to a significant reduction in the tonal noise and also an improvement in the performance. However, this trend is only valid up to a certain number of blades, and a further increment might reduce the aerodynamic performance of the fan. Besides modifying the impeller geometry, new volute tongues are designed and manufactured. It is demonstrated that the shape of the volute tongue plays an important role in the tonal noise generation of the fan. It is possible to reduce the tonal noise by using stepped tongues which produce phase-shift effects that lead to an effective local cancellation of the noise.


2010 ◽  
Vol 146-147 ◽  
pp. 1524-1528 ◽  
Author(s):  
Xue Zhi Wang ◽  
Zong Chao Xu ◽  
Zhong Bi ◽  
Hao Wang

The wedge splitting test specimens with three series of different relative crack length were used to study the influences of relative crack length on the fracture toughness of common concrete. The suitable formulation for fracture toughness of concrete with different relative crack length was gotten on comparing between fracture toughness test results and computation results of the model developed from Hu formula.


Author(s):  
Harish R ◽  
Ramesh S ◽  
Tharani A ◽  
Mageshkumar P

This paper presents the results of an experimental investigation of the compressive strength of concrete cubes containing termite mound soil. The specimens were cast using M20 grade of concrete. Two mix ratios for replacement of sand and cement are of 1:1.7:2.7 and 1:1.5:2.5 (cement: sand: aggregate) with water- cement ratio of 0.45 and varying combination of termite mound soil in equal amount ranging from 30% and 40% replacing fine aggregate (sand) and cement from 10%,15%,20% were used. A total of 27 cubes, 18 cylinders and 6 beams were cast by replacing fine aggregate, specimens were cured in water for 7,14 and 28 days. The test results showed that the compressive strength of the concrete cubes increases with age and decreases with increasing percentage replacement of cement and increases with increasing the replacement of sand with termite mound soil cured in water. The study concluded that termite mound cement concrete is adequate to use for construction purposes in natural environment.


2014 ◽  
Vol 919-921 ◽  
pp. 1794-1800
Author(s):  
Xin Zhi Zheng ◽  
Xin Hua Zheng

Abstract: 7 square steel tubular columns were tested to discuss the ultimate axial bearing capacity, ductility performance and the steel consumption under stiffened by steel belts and binding bars of different cross-sections. Test results indicate that only by increasing fewer amounts of steel usage, stiffened square CFST columns with binding bars can not only improve the overall effects of restraint and alleviate regional local buckling between the binding bars, but also improve the bearing capacity of concrete filled square steel tubular columns. The utility benefits and the economical benefit is considerable, deserving extensive use.


Author(s):  
H. R. Born

This paper presents an overview of the development of a reliable bearing system for a new line of small turbochargers where the bearing system has to be compatible with a new compressor and turbine design. The first part demonstrates how the increased weight of the turbine, due to a 40 % increase in flow capacity, influences the dynamic stability of the rotor-bearing system. The second part shows how stability can be improved by optimizing important floating ring parameters and by applying different bearing designs, such as profiled bore bearings supported on squeeze film dampers. Test results and stability analyses are included as well as the criteria which led to the decision to choose a squeeze film backed symmetrical 3-lobe bearing for this new turbocharger design.


Author(s):  
Yong-Hoon Shin ◽  
Il Soon Hwang ◽  
Massimiliano Polidori ◽  
Paride Meloni ◽  
Vincenzo Casamassima ◽  
...  

As one of the Generation-IV reactor concepts, lead-alloy-cooled advanced nuclear energy systems (LACANES) have been studied worldwide in order to utilize the advantages of good heat transfer properties, neutron transparency and chemical inertness with air and water. Since the Fukushima accident, the passive safety aspect of the LACANES is increasingly emphasized due to outstanding natural circulation capability. To investigate the thermal-hydraulic capability of LBE, an international cooperation has been performed under OECD/NEA program, under the guidance of the Nuclear Science Committee by a task force named as Lead Alloy Cooled Advanced Nuclear Energy Systems (LACANES) since 2007. This international collaboration had dealt with computational benchmarking of isothermal LBE forced convection tests in the phase I, and the working group published a guideline for using one-dimensional system codes to simulate LBE forced circulation test results from HELIOS loop. The phase II was started after that, to give an additional guideline in the case of natural circulation. NACIE, one of benchmarking targets for the phase II which is a rectangular-shape loop located at ENEA-Brasimone Research Centre, Italy. NACIE test results were benchmarked by each participant using their one-dimensional thermal-hydraulic codes, and they are to follow the guideline from the LACANES phase I for regions where hydraulic loss occurs. Due to the selection of hydraulic loss coefficient relations by users, the cross-comparison results of international participants showed some discrepancies and the estimated mass flow rates had 13% of maximum error. Also, the future R&D areas are identified.


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