Performance Influence of Fluid Viscosity on the Single-phase Fluid Loop

Paper number

IAC-07-C3.3.05

Author

Dr. Yufeng Fan, China Academy of Space Technology (CAST), China

Coauthor

Mr. Jiarong Huang, China

Year

2007

Abstract

Generally, fluid temperature reduces when the heat load is smaller than the designed one transported in the single-phase fluid loop for use in spacecraft thermal control. Because of temperature change, it leads to the change of fluid viscosity, the increase or decrease of fluid loop hydraulic loss, the running parameters change of loop components (such as recirculating pump, three-way valve), and so on.
The viscosity is the function of fluid temperature defined by fluid physical property. In general, the temperature is lower and the viscosity is bigger. In theory, the longitudinal hydraulic loss coefficient is the function of the fluid viscosity. Especially, in the condition of laminar flow,it is a linear function. To the whole single-phase fluid loop, the hydraulic loss   is composed of the longitudinal loss   and partial loss  . 
It is generally thought that the temperature decreases and the hydraulic loss of the single-phase fluid loop accordingly increases. However, in the single-phase fluid loop using in spacecraft thermal control, the partial loss is the main aspect of the hydraulic loss because of the contradiction between a large numbers of the loop components and the limited layout space.
At first, this paper presents the theoretical analysis applying the experiential formula to evaluate the influence of the temperature (or viscosity) on fluid loop and recirculating pump. In addition, some experiments had been carried out, and the results show the similar conclusion with theoretical analysis, which the fluid viscosity has had the little influence on the hydraulic loss of the single-phase fluid loop system and the running parameter of recirculating pump. These results will give some help for the design of the single-phase fluid loop and the selection of fluid in the thermal management system.

Abstract document

IAC-07-C3.3.05.pdf

Manuscript document

IAC-07-C3.3.05.pdf (🔒 authorized access only).

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