The bubble, drop, and particle unit (BDPU)
- PDF / 486,065 Bytes
- 5 Pages / 594 x 774 pts Page_size
- 93 Downloads / 171 Views
I.
INTRODUCTION
THE purpose of this document is to inform potential users about the capabilities of the Bubble, Drop, and Particle Unit (BDPU). As part of the ESA Microgravity Research Programme, the BDPU facility has been conceived and developed to offer European and United States experimenters opportunities to conduct research on fluid phenomena in Spacelab's microgravity environment. This facility is capable of handling and stimulating bubbles and drops in various ways; it has been primarily designed in view of optical investigations of transparent fluids.
II.
SCIENTIFIC OBJECTIVES
It is known that a microgravity environment enables investigation of fluid phenomena which cannot be analyzed in the gravity conditions prevailing at the earth's surface. For instance, surface tension effects can be isolated from gravityinduced convection and therefore can be better understood. BDPU has been designed to perform several types of fluid experiments which could benefit from a reduced gravity, and in particular experiments involving bubbles, drops, and particles. Possible research topics are the following: 1. the behavior of bubbles and drops under the influence of temperature gradients, 2. convection cell experiments, and 3. the interaction between a moving solidification front and intrusions. Scientists are interested in determining the temperature, the density, and the location of inhomogeneities within the fluid cell as well as in their temporal evolution. The main
A. GONFALONE, Project Manager, and T. DEWANDRE, Engineer, are with European Space Agency, Microgravity Division, Postbus 299, 2200 AG Noordwijk, The Netherlands. This paper is based on a presentation made in the symposium "Experimental Methods for Microgravity Materials Science Research" presented at the 1988 TMS-AIME Annual Meeting in Phoenix, Arizona, January 25-29, 1988, under the auspices of the ASM/MSD Thermodynamic Data Committee and the Material Processing Committee.
METALLURGICALTRANSACTIONS A
mean BDPU provides to measure them is the optical monitoring of the corresponding changes of refraction index.
III.
DESCRIPTION OF BDPU
A. General
The BDPU is composed of three interconnected rack elements: the electronic module, the video recorder module, and the experiment module (Figure 1). The electronic module provides the power supply, the electronics, and the data handling capabilities of BDPU. The video recorder module records simultaneously images from two video cameras and from a thermographic camera. The experiment module (Figures 2 and 3) houses a sliding optical module (Figure 4) which contains the optical diagnostic elements and the exchangeable test (or fluid) cell (Figure 5). Within the experiment module, the test fluid can be submitted to a variety of stimuli (thermal, mixing, injection, and extraction of bubbles/ drops) and it can also be monitored by sensors (temperature, pressure). The test container (30 • 15 x 15 cm 3 maximum) is defined as the test cell together with its dedicated equipment (injection system, fluid reservoir, e
Data Loading...
