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Show A number of new concentration measurement techniques are currently being developed based on laser absorpt10n techn1Ques. The overall schematic of a typical system 1s shown 1n F1gure 3. As d1scussed by Grant (22) absorption spectrophotometry is a technique that can Quant1tat1vely measure the concentration of some spec1es, can be performed in-situ, ~nd can respond rap1dly to changes 1n concentratlOn. We also note that an additlonal advantage of such a l1ght attenuat10n technique Is Its sultabl1ity for measuring the concentration of particles should testing w1th a sol1d tracer be desired. Attenuat10n will be due to scattering rather than absorption, but Be.er's Law should stlll be obeyed for dilute suspenslons. r-l&S£A 8EU / I UIoIPI.£ t DI$CH&IIG£ Fig 3 - Laser Absorption Spectophotometer EXPERIMENTAL INSTRUMENTATION AND FACILITIES Mechan1cal Systems Engineering (MSE), 1s one of seven groups within Combust10n Engineering's Kreislnger Development Laboratory (RDL), an advanced research and development facl1ity concentrating on fossil power energy conversion systems. MSE has been assigned the technological responsibility for single phase and two component non-reactive fluid mechanics, convective heat and mass transfer, v1bration stress and structural analysis, and erosion and abras10n analysis. It is also responsible for the construction and evaluation of phys1cal models of gas, ai~, and atr/sol1ds handling equipment associated with steam generators and auxiliary equipment. The following sections describe the most recent instrumentation, facil1ties, and experimental results obtained from isothermal flow models. 120 INSTRUMENTATION - A number of techniques are used to obtain engineering data from the Isothermal models evaluatea at KDL. These Include flow visual1zat10n, veloc1ty mapPln l g, abnld concentration measurement. The most app rca e of these are discussed next. F10~ Visualtzation - Flow vlsual1zation tec n1Ques using smoke have been one of the primary methods of analyzing furnace aerodynamic patterns. Two methods of smoke generat10n are currently 1n use- commercially available smoke bombs and a liquid-based smoke generator. The commercial smoke bombs are compr1sed of a heavy cardboard tube f1lled with a mater1al that creates a dense white smoke when combusted. Recently, a system was developed where p01nt In1ection is created by Igniting a smoke bomb {hen placing it Into a sealed conta1ner. Up to four Injector tubes are provided from this container for transporting the smoke to various pOints in the model. We note that disadvantages to this method include problems with l1mitfng the amount of smoke generated and the slightly corrosive and difficuTt to remove residue that Is produced from the smoke generator. To correct these prob I ems, a new smoke generator is in use that uses the heating of an 011 f>ased material for generating the smoke. This system 1s more controllable and permits the introduct1on of smoke at any p01nt w1th1n the model volume. In add1t10n, for the determination of local flow direction, s1ngle multiple yarn tuft arrays are used for flow visualization. Also, for burner flow models -( see Reference 6 ), small helium f1lled soap bubbles are used to track the overall flow patterns and to identify flow recirculat10n zones. The results of all flow visualization tests are recorded either by st i 11 or color photographiC means. For recording smoke tests, better results are obtained dur1ng {he recording process if color reversal Is used. Velocity Measurement - A number of different techniques are currently in use as well as under development by Combustion Engineering. The most extensively used technique 1s baseiJ on the use of a mult1-hole pitot tube manipulated by ~n automatic probe traversing device (APTD). ThiS computer controlled device positions and rotates the probe at preselected locat10ns within the flow model and can resolve the flow velocity 1nto its major components. The data obtained from this system Is automatically transferred to the laboratory's mainframe computer for reduction and analys1s. For maximum experimental accuracy, we perform probe cal1brations before and after each test program. A sample velocity output plot from this system is shown In Figure 4. Also In use Is a two axis laser doppler anemometer. This velocity measurement system is extensively used in applications where the measured velocities are very low and/or the measurements must be made nonintrusively. It is also used In appl1cat10ns where the determination of turbulence intensity is required. |