Abstract: An apparatus and method for determining particle character moving with a vertical fluid flow towards a multiplet of calibrated sediment traps. The number N of measuring locations, which coincides with the number of n different particle groups (Pn) occurring at all of them, with N (N=n) different types of sediment traps (TN) the mass accumulations (MTN) and the sinking/raising velocity spectrum (VW) of the n particle groups are determined. Upon formulation and solution of a linearly independent system of [N] accumulation equations under incorporation of the established calibration and measurement parameters, the sought-after in-situ mass flux [(ISM)Pn] and the derived in-situ total mess flux [(ISM)p] is obtained.

Abstract: It is generally known that the mass accumulation increasing with time in sediment traps is governed by principles which are determined by the trap, flow and particle characteristics at the location of collection. Inferences about the vertical in-situ mass flux of n different particle groups are not possible, though. The reported use of several traps for a statistical confirmation of the collection result leads to no conclusion about this relevant parameter as well. Thus, the newly invented procedure provides for such means, in that at a number N of measuring locations, which coincides with the number of n different particle groups (Pn) occurring at all of them, with N (N=n) different types of sediment traps (TN) the mass accumulations (MTN) and the sinking/raising velocity spectrum (VW) of the n particle groups are determined.

Abstract: A method and apparatus is provided to measure in fluids including suspensions and heterogeneous mixtures time-resolved histories of velocity magnitude and vector of unidirectional, unsteady and oscillating flows. A boundary layer develops from a sharp, leading edge of a plate approached by fluid flow. Its skin friction, measured at a fixed location on the plate by a hot-film sensor connected to a constant-temperature anemometer, is uniquely related to the magnitude of the approach velocity. Temperature-sensing gauges within the range of the thermal wake from the skin friction sensor allow to determine direction of the flow.

Abstract: A method is provided to generate over a confined space precisely defined distributions of the magnitude of the wall shearing stresses in a substrate/fluid boundary layer. A fluid flow is rotated around a center axis in the confined space. Simultaneously a defined fluid volume is removed in the rotational axis of the flow per unit time and recirculated or replenished through return openings in the lid or sidewall.

Abstract: A method and apparatus is provided to generate over a confined space precisely defined distributions of the magnitude of the wall shearing stresses in a substrate/fluid boundary layer. A fluid flow is rotated around a center axis in the confined space. Simultaneously a defined fluid volume is removed in the rotational axis of the flow per unit time and recirculated or replenished through return openings in the lid or sidewall.