Preliminary Draft Selection of Geometrical Parameters in External and Internal Spur and Helical Gears in Automotive Drive Lines

1984 ◽  
Author(s):  
Z. Jaśkiewicz ◽  
A. Wasiewski
Keyword(s):  
Geometrical Parameters ◽  
Helical Gears ◽  
Preliminary Draft ◽  
Selection Of

Influence of geometric parameters of screw nozzles of twin-screw extruder-press on oil yield

2021 ◽  
Vol 12 (3) ◽  
Author(s):  
M. M. Gudzenko ◽  
◽  
V. P. Vasyliv ◽  
M. M. Mushtruk ◽  
M. M. Zheplinska ◽  
...  
Keyword(s):  
Free Volume ◽  
Geometric Parameters ◽  
Oil Yield ◽  
General Nature ◽  
Geometrical Parameters ◽  
Twin Screw Extruder ◽  
Screw Extruder ◽  
Twin Screw ◽  
Working Bodies ◽  
Selection Of

In modern economic conditions, the chosen technology of raw material processing and the choice of the necessary equipment for both the line as a whole and the oil press are of great importance in oil production. In small-capacity workshops, screw presses of various designs are used. The twin-screw extruder occupied a certain niche among the press equipment with a productivity of 150–500 kg/h. Their use can significantly simplify the technology of oilseed processing. They combine operations of heat treatment, grinding, and pressing of vegetable oil. It is important to study the influence of geometric parameters of the oil pressure path and screw nozzle on the oil yield. In twin-screw extruders, it is rational to choose the pitch of the worm, the width of the channel between the turns, the width of the crest of the turn and the length of the nozzle with variable geometrical parameters. The analysis and selection of geometrical parameters of working bodies of a twin-screw extruder on the basis of theoretical calculations are carried out. Two sets of experimental working bodies with the changed geometrical parameters are made. Their theoretical degree of compression is determined, which is 5.50, 4.69, and 4.33, respectively. It is experimentally confirmed that the oil yield depends on the degree of compression due to the geometric parameters of the screw. The effect of a sharp drop in the free volume of the screw on the energy performance and press extruder performance has been revealed. The general nature of the change in the free volume in the areas of nozzle groups is accompanied by an uneven decrease of 40–80% towards the release of oil cake. The nature of the change in the free volume of turns along the length of the screw shaft characterizes the correctness of its design. The selection of rational geometric parameters of the working bodies should be considered in combination with other design parameters, which will intensify the process of oil pressing.

Influence of Undercut on the Load Capacity for Involute Teeth With Small Pressure Angle

2003 ◽  
Author(s):  
Jose´ I. Pedrero ◽  
Mariano Arte´s ◽  
Carlos Garci´a-Masia´
Keyword(s):  
Load Capacity ◽  
Geometrical Parameters ◽  
Contact Ratio ◽  
Helical Gears ◽  
Small Pressure ◽  
Pressure Angle ◽  
Number Of Teeth ◽  
Minimum Number

The minimum number of teeth to avoid undercut on involute spur and helical gears depends on the pressure angle, among some other geometrical parameters. Higher number of teeth is required if the pressure angle becomes smaller. However, the contact ratio may be increased by reducing the pressure angle, which means the load is distributed along a longer line of contact. In many cases, even if undercut arises and teeth are weakened, both effects may result in higher load capacity for the gears. This paper presents a study on the influence of the pressure angle on the contact ratio, and through it on the length of contact and the load capacity, including a discussion on the condition to improve the load capacity by reducing the pressure angle beyond the undercut limit.

A Model for the Estimation of Pressure Ripple in Tandem Gear Pumps

2015 ◽  
Author(s):  
Mattia Battarra ◽  
Emiliano Mucchi ◽  
Giorgio Dalpiaz
Keyword(s):  
High Pressure ◽  
Dynamic Behavior ◽  
Low Pressure ◽  
Variable Pressure ◽  
Geometrical Parameters ◽  
Gear Pump ◽  
Helical Gears ◽  
Pressure Stage ◽  
Outlet Pressure ◽  
Pressure Ripple

The present paper addresses the development of a lumped parameters model used to analyze the dynamic behavior of a so-called tandem gear pump. The pump is composed of two coaxial stages, both with external gears: a high pressure stage with spur gears and a low pressure one with helical gears. In particular, the paper deals with the modelling and the analysis of the phenomena bound to the pressure distribution around the gears, since they have the most important effect in the dynamic behavior of the pump. The pressure variation in the inlet and outlet chambers, the variable pressure in the trapped volume as well as the pressure evolution from the low to the high pressure chamber is estimated based on the Euler’s approach. The model is developed in Matlab environment. Attention is particularly focused on the description of the methodology adopted for modelling the low-pressure stage, constituted by helical gears, and its influence on the calculation of the pump geometrical parameters. The results provided by the numerical model are compared with experimental measurements in terms of outlet pressure ripple and volumetric efficiency under different working conditions. The results of the validation can be considered satisfactory. Predicted pressure ripple is shown and the effects of interconnections between stages are analyzed studying the outlet pressure ripple in the frequency domain as well.

Analysis of the Fin Performance of Offset Strip Fins Used in Plate-Fin Heat Exchangers

2016 ◽  
Vol 138 (10) ◽  
Author(s):  
Yujie Yang ◽  
Yanzhong Li ◽  
Biao Si ◽  
Jieyu Zheng ◽  
Rui Kang
Keyword(s):  
Heat Transfer ◽  
Mass Flux ◽  
Heat Exchangers ◽  
3D Models ◽  
Geometrical Parameters ◽  
Height Ratio ◽  
Fin Efficiency ◽  
Fin Thickness ◽  
Offset Strip Fin ◽  
Selection Of

As an important consideration in the design of plate-fin heat exchangers, the selection of plate-fin surfaces is associated with the estimation of the fin performance in many cases. The fin performance of offset strip fin (OSF) and plain fin is numerically investigated with well-validated 3D models in the present study. The comparative analysis shows that the conventional fin efficiency and fin effectiveness concepts provide an incomplete assessment of the fin performance of the fins, and lead to impractical suggestions of using OSF fin. Further investigation indicates that the idealization of uniform heat transfer coefficient over all the surfaces in fin channel, which runs through the conventional concepts, is untenable, and strongly restricts the fin performance analysis. An actual fin effectiveness is then proposed to measure the fin performance. It physically represents the ratio of the heat flux over the fin surfaces and that over the primary surfaces in the fin channel. With this method, the effects of the geometrical parameters of the OSF are discussed carefully. The results show that there exists a specific fin thickness-to-height ratio α and fin density γ, which contribute to the highest fin performance for a given mass flux, and the optimal γ (or α) increases (or decreases) as mass flux increases. The OSF fins with relatively large fin thickness-to-length ratio δ perform better in low Re region and the optimum δ decreases with the increasing Re number.

scholarly journals Energy Absorbing Effectiveness – Different Approaches

2018 ◽  
Vol 12 (1) ◽  
pp. 54-59 ◽  
Author(s):  
Maria Kotełko ◽  
Mirosław Ferdynus ◽  
Jacek Jankowski
Keyword(s):  
Impact Load ◽  
Geometrical Parameters ◽  
Foam Filled ◽  
Thin Walled ◽  
Energy Absorbers ◽  
Energy Absorbing ◽  
Selection Of

AbstractIn the paper the study of different crashworthiness indicators used to evaluate energy absorbing effectiveness of thin-walled energy absorbers is presented. Several different indicators are used to assess an effectiveness of two types of absorbing structures, namely thin-walled prismatic column with flaws and thin-walled prismatic frustum (hollow or foam filled) in both cases subjected to axial compressive impact load. The indicators are calculated for different materials and different geometrical parameters. The problem of selection of the most appropriate and general indicators is discussed.

scholarly journals Condition monitoring of helical gears using automated selection of features and sensors

Measurement ◽  
2016 ◽  
Vol 93 ◽  
pp. 164-177 ◽  
Author(s):  
H. Alkhadafe ◽  
A. Al-Habaibeh ◽  
A. Lotfi
Keyword(s):  
Condition Monitoring ◽  
Helical Gears ◽  
Selection Of

Parameter Selection of Fluid Dynamic Sealing for a Submersible Slurry Pump

2006 ◽  
Author(s):  
Hongjuan Ran ◽  
Xianwu Luo ◽  
Hongyuan Xu ◽  
Wen Luo ◽  
Junqi Peng
Keyword(s):  
Solid Particle ◽  
Yellow River ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Design Concept ◽  
Geometrical Parameters ◽  
Mechanical Seal ◽  
River Sand ◽  
Actual Operation ◽  
Selection Of

In the case of slurry pumps, mechanical seal is usually used. It is well known that the pump is very dangerous if any solid particle enters the seal. Nowadays, people prefer to install a fluid dynamic sealing including 1 or 2 sets of minor vanes and an auxiliary impeller rather than using high-pressure cleaning water in a slurry pump. However, if a fluid dynamic sealing is not designed properly, the mechanical seal is apt to be destroyed by the invading solid particle, and the slurry pump axes is worn seriously and rapidly. Though there are few empirical methods for designing a fluid dynamic sealing, the definite design concept is much deficiency. In the present work, the geometry selection of the fluid dynamic sealing for a submersible slurry pump is carried out so as to establish the basic principle for a fluid dynamic sealing design. The model pump is of centrifugal type, and has the specific speed of 136 m·m3/min·rpm. In order to validate the design concept, three dimensional turbulent flow in the pump was simulated. The total pump channel including inlet pipe, impeller with attached minor vane set, volute casing, and auxiliary impeller is treated as the calculation domain. The mesh grid is more than 2,000,000 nodes. The numerical simulation has been conducted by using a commercial code Fluent v6.1.2. To see the effect of minor vanes and auxiliary impeller geometrical parameters on the sealing performance, we change vane number, vane height, and radius of the minor vanes and auxiliary impeller, flow-rate of sealing water, etc. Based on the numerical results, a set of favorable geometrical parameters of the fluid dynamic sealing was selected for a submersible slurry pump. It is noted that the pump with the newly designed fluid dynamic sealing had been successfully applied for actual operation in the Yellow River sand transportation system in Shandong province, China.

Design and Fabrication of a Winged Hybrid Airship Model for IIUM-LSWT

2015 ◽  
Vol 1115 ◽  
pp. 513-516
Author(s):  
Anwar Ul Haque ◽  
Nik Mohamad Amri Hafiz ◽  
S.M. Kashif ◽  
Waqar Asrar ◽  
Ashraf Ali Omar ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Geometrical Parameters ◽  
Wind Tunnel Testing ◽  
Contributing Factors ◽  
Wind Tunnel Model ◽  
Manufacturing Method ◽  
Tunnel Model ◽  
Design And Manufacturing ◽  
Low Speed Wind Tunnel ◽  
Selection Of

Wind Tunnel Testing on a subscaled model of a winged hybrid airship requires a faithful reproduction of all geometric details of actual airship. Due to huge volume of hull, geometrical parameters of such airships are quite different from that of an aircraft. In this article, a scheme for designing such models is described alongwith a review of different strategies available for manufacturing of its prototype wind tunnel model in IIUM low speed wind tunnel. Similar to aircrafts, major contributing factors for scaling, design and manufacturing of a subscaled model of hybrid airships are discussed. It is concluded that the required aerodynamic data will be the dictating factor for selection of the manufacturing method.

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