Analysis of load conditions of piston pump unit cylinder under temperature effects

2019 ◽  
Author(s):  
I. P. Aistov ◽  
K. A. Vansovich ◽  
S. S. Busarov ◽  
D. S. Titov
Keyword(s):  
Temperature Effects ◽  
Piston Pump ◽  
Pump Unit ◽  
Load Conditions

Cavitation in a high-speed aviation axial piston pump over a wide range of fluid temperatures

2021 ◽  
pp. 095765092110469
Author(s):  
Qun Chao ◽  
Zi Xu ◽  
Jianfeng Tao ◽  
Chengliang Liu ◽  
Jiang Zhai
Keyword(s):  
Temperature Effects ◽  
Pressure Pulsation ◽  
Piston Pump ◽  
Limiting Factors ◽  
Fluid Temperature ◽  
Cfd Model ◽  
Axial Piston Pump ◽  
Wide Range ◽  
Fluid Properties ◽  
Axial Piston

The axial piston pump in aerospace applications needs to operate over a wide range of fluid temperatures from −54°C to 135 °C. The fluid properties at such extreme temperatures will significantly affect the cavitation that is one of the major limiting factors for the efficiency and reliability of aviation axial piston pumps. However, it appears that very little of the existing literature studies the effects of extreme fluid temperatures on the pump cavitation. This paper aims to examine the temperature effects on the cavitation in an aviation axial piston pump. First, we develop a three-dimensional (3D) transient computational fluid dynamics (CFD) model to investigate the pump cavitation and validate it experimentally. Second, we use the validated CFD model to investigate the temperature effects on the pump cavitation by changing the fluid properties including viscosity, density, and bulk modulus. The numerical results show that low fluid temperature makes the aviation axial piston pump suffer serious cavitation due to high viscosity, leading to delivery flow breakdown, unacceptable pressure pulsation, and delayed pressure built up. In contrast, high fluid temperatures have minor effects on the cavitation although they increase the pressure pulsation and built-up time slightly.

Heuristics for the Periodic Mobile Piston Pump Unit Routing Problem

2015 ◽  
Vol 5 (1) ◽  
pp. 1-25
Author(s):  
Marcos R. Q. Andrade ◽  
Luiz S. Ochi ◽  
Simone L. Martins
Keyword(s):  
Local Search ◽  
Oil Wells ◽  
Experimental Results ◽  
Piston Pump ◽  
Pump Unit ◽  
Search Methods ◽  
Routing Problem ◽  
Work Shift ◽  
Local Search Methods ◽  
Limited Duration

The Periodic Mobile Piston Pump Unit Routing Problem consists of, given a set of surface oil wells scattered over an onshore producing field, determining routes for each day of work, with limited duration work shift, that maximize the collection of oil carried by a mobile piston pump unit. This paper presents different construction and local search methods used in the composition of GRASP and ILS heuristics for the problem. Experimental results demonstrate the effectiveness of the proposed method.

Improving the Energy Efficiency of a Hydraulic Press Via Variable-Speed Variable-Displacement Pump Unit

2018 ◽  
Vol 140 (11) ◽  
Author(s):  
Haihong Huang ◽  
Rui Jin ◽  
Lei Li ◽  
Zhifeng Liu
Keyword(s):  
Energy Efficiency ◽  
Hydraulic Press ◽  
Variable Speed ◽  
Pump Unit ◽  
Forming Process ◽  
Drive Unit ◽  
Rotating Speed ◽  
Displacement Pump ◽  
Variable Displacement ◽  
Load Conditions

Hydraulic presses are widely applied in various forming processes to manufacture products with complex shapes, however, they are energy-intensive. In order to lower the energy consumption, a variable-speed variable-displacement pump unit (SVVDP) was developed for hydraulic presses, where the flow rate required by the press in a forming process can be realized by changing the motor rotating speed and the pump displacement simultaneously. A theoretical model was built to reveal the energy dissipation behavior of the drive unit, which shows that the energy efficiency of the drive unit can be optimized by varying the rotating speed of the motor under a variety of load conditions. An experimental platform with a SVVDP was established to find the optimum rotating speed and the corresponding displacement in different load conditions, and experimental results verified the improved energy efficiency of the SVVDP compared with that of the commonly used single variable drive unit. By employing the strategy that the determined optimum rotating speeds in different load conditions were preset as recommended values for the drive unit working in different operations, the proposed drive unit was applied to a press completing a forming process and the results indicate significant energy saving potentials.

Characterization of carbides in M50NiL

1991 ◽  
Vol 49 ◽  
pp. 606-607
Author(s):  
L. S. Lin ◽  
K. P. Gumz ◽  
A. V. Karg ◽  
C. C. Law
Keyword(s):  
Temperature Effects ◽  
Base Composition ◽  
Lattice Parameter ◽  
Control Surface ◽  
Carbide Formation ◽  
Particle Sizes ◽  
Low Carbon ◽  
Fee Structure ◽  
Heat Treated

Carbon and temperature effects on carbide formation in the carburized zone of M50NiL are of great importance because they can be used to control surface properties of bearings. A series of homogeneous alloys (with M50NiL as base composition) containing various levels of carbon in the range of 0.15% to 1.5% (in wt.%) and heat treated at temperatures between 650°C to 1100°C were selected for characterizations. Eleven samples were chosen for carbide characterization and chemical analysis and their identifications are listed in Table 1.Five different carbides consisting of M6C, M2C, M7C3 and M23C6 were found in all eleven samples examined as shown in Table 1. M6C carbides (with least carbon) were found to be the major carbide in low carbon alloys (<0.3% C) and their amounts decreased as the carbon content increased. In sample C (0.3% C), most particles (95%) encountered were M6C carbide with a particle sizes range between 0.05 to 0.25 um. The M6C carbide are enriched in both Mo and Fe and have a fee structure with lattice parameter a=1.105 nm (Figure 1).

Sign in / Sign up

Export Citation Format

Share Document