DESCRIPTION

Technical Description

HM 145 can be used to study seepage and groundwater flows after precipitation. Furthermore, sediment transport in courses of rivers is also presented in the context of flow obstacles. Variable precipitation density and areas and different groundwater supply and drain possibilities allow a wide variety of experiments.

HM 145 contains a closed water circuit with storage tank and pump. The core element is a sand-filled, stainless steel experiment tank with inclination adjustment. To study precipitation, a precipitation device is available, which is equipped with a timer to define the times of precipitation. The precipitation device consists of two groups of four nozzles. Water can flow in (groundwater) or out (drainage) via two chambers on the side. The experiment tank is separated from the chambers by fine mesh screens. To study the lowering of groundwater, two wells with open seam tubes are available. By means of a small weir in the in the supply and drain, a course of a river can be generated. Different water levels can be generated. Water supply and water drain can be opened and closed, thus allowing a wide variety of experimental conditions. In addition, three different models make it possible to study the flow around obstacles and the resulting sediment transport in the river bed.

At the bottom of the experiment tank there are measuring connections to detect groundwater levels, which are displayed on 19 tube manometers. Two flow meters with different measuring ranges indicate the supply to the experiment tank. A measuring tank at the drain contains a measuring weir for determining the water level and a force sensor for determining the amount of sediment.

The measured values are indicated at the trainer. At the same time, the measured values can also be transmitted directly to a PC via USB. The data acquisition software is included. 

The well-structured instructional material sets out the fundamentals and provides a step-by-step guide through the experiments.

Learning Objectives / Experiments

- investigating transient processes 
  * effect of rainfall of varying duration on the discharge
  * storage capacity of a soil
- investigating steady processes
  * seepage flow 
  * effects of wells on the groundwater level over time 
- flow behaviour of rivers, obstacles in the river bed, sediment transport in rivers