MDPI - Publisher of Open Access Journals

20 pages, 7736 KiB

Open AccessArticle

A Three-Dimensional Body Force Modeling of Fans in Windmilling Condition and Its Application

by Qingguo Kong and Wei Jia

Aerospace 2023, 10(8), 724; https://doi.org/10.3390/aerospace10080724 - 18 Aug 2023

Cited by 3 | Viewed by 2155

To investigate the aerodynamic characteristics of the fan in windmilling conditions, a new body force model with the fan rotational speed prediction model was developed. The fan rotational speed prediction model was built based on the balance of fan output torque and resistance torque. The rotational speed of the fan spool can be iteratively solved simultaneously with solving the governing equations without requiring mass flow rate or other inputs. The comparison with the experimental results shows that using the body force model can accurately predict the rotational speed of the fan spool under different operating conditions. The radial distribution of flow parameters can be obtained. Moreover, numerical simulations of the fan under different circumferential total pressure distortion inflow conditions were conducted using the body force model. The results show that, unlike the design point and non-design point at which the fan operates normally, the high radius region of the fan is in the “turbine mode” while the low radius region is in the “compressor mode” under windmilling conditions. The different effects on the longitudinal vortex in the two regions deepen and alleviate the circumferential distortion, respectively. There are strong circumferential and radial pressure gradients at the junction of the distortion-affected zone and the non-distortion-affected zone, adding additional mixing losses. Full article

► Show Figures

Figure 1

16 pages, 6264 KiB

Open AccessArticle

Conceptual Design of Electromechanical Actuation Systems for Large-Sized Directional Control Valves

by Tobias Vonderbank and Katharina Schmitz

Actuators 2021, 10(6), 133; https://doi.org/10.3390/act10060133 - 16 Jun 2021

Cited by 1 | Viewed by 3861

Abstract

Increasing performance in modern hydraulics is achieved by a close investigation of possible enhancements of its components. Prior research has pointed out that electromechanical actuators can form suitable alternatives to hydraulically piloted control systems. Since the requirements at these actuation systems depend on the operating conditions of the system, each actuator can be optimized to the respective hydraulic system. Considering that many different conceptual designs are suitable, the phase of conceptual design plays a decisive role during the design process. Therefore, this paper focuses on the process of developing new conceptual designs for electromechanical valve actuation systems using the method of function structures. Aiming to identify special design features, which need to be considered during the design process of electromechanical actuation systems, an exemplary actuator was designed based on the derived function structure. To highlight the potential of function structures for the development of new electromechanical valve actuation systems, two principal concepts, which allow the reduction of the necessary forces, have been developed by extending the function structure. These concepts have been experimentally investigated to identify their advantages and disadvantages. Full article

(This article belongs to the Special Issue Selected Papers from the 1st International Electronic Conference on Actuator Technology: Materials, Devices and Applications (IeCAT))

► Show Figures

Figure 1

10 pages, 1265 KiB

Open AccessProceeding Paper

Design of Electromechanical Actuators for Large Sized Valves

by Tobias Vonderbank and Katharina Schmitz

Proceedings 2020, 64(1), 37; https://doi.org/10.3390/IeCAT2020-08477 - 20 Nov 2020

Cited by 1 | Viewed by 1386

Abstract

Increased performance in modern hydraulics is achieved by crucial investigation of possible enhancements of its components. Previous research has pointed out that electromechanical actuators can represent an alternative to hydraulic pilot control systems. Since an additional pilot circuit is complex and expensive, there are advantages, especially for systems which currently rely on a separate hydraulic pilot circuit. Actuators for large sized valves have to meet various requirements, such as applying high forces over large strokes. A functional structure of the “valve and its actuation system” has been derived to define these requirements effectively in order to develop an innovative valve actuator. The general function of the system is divided into elementary functions using this design method. Besides common actuators consisting of a switch and an energy converter, even more alternative actuator designs were pointed out by the comprehensive analysis of the functional structure. Since every actuator needs to be attached on any regular hydraulic valve, the designed actuator is presented, and the most significant construction details are explained. In conclusion, this paper summarizes significant steps during the design process of alternative electromechanical actuators of hydraulic valves. It is intended to serve as a basis for the further development of innovative valve actuators. Full article

(This article belongs to the Proceedings of The 1st International Electronic Conference on Actuator Technology: Materials, Devices and Applications)

► Show Figures

Figure 1

Search Results (3)

Further Information

Guidelines

MDPI Initiatives

Follow MDPI

Saved Queries

Search Filter Reset All

Years

Feature Papers

Subjects

Journals

Article Types

Countries / Regions

Search Results (3)

Further Information

Guidelines

MDPI Initiatives

Follow MDPI