Application of nonaxisymmetric casing treatments (CTs) can extend the operating range of a transonic compressor significantly. Recent CT designs have proven successful at achieving operating range extension without efficiency loss under design conditions. Two different CT designs were investigated on a high-speed one and a half stage test rig using extensive instrumentation. The stage setup is representative of the front stage of a modern high-pressure compressor. Results of particle image velocimetry (PIV) measurements taken in the blade tip region underneath the CT show a significantly modified flow structure compared to the smooth casing reference case. Blockage zone, secondary flow, and shock structures are affected by the CT, especially in highly throttled operating conditions. The stall inception process of the system with axial slots shows unexpected behavior, with modal activities that are not observed without CT. These activities are resolved using unsteady wall pressure (WP) and hot wire measurements.

A new transonic compressor test rig for gas turbine front stages was commissioned at the Technical University of Darmstadt in 2018. In the first measurement campaign numerous transient stall maneuvers were conducted by throttling the compressor beyond its stability limit. Several distinct phenomena can be observed during in-stall operation. This work gives an overview of those different manifestations of stall with focus on classification and characterization. For this purpose, detailed post-processing and unsteady data analysis are conducted providing information in terms of operating points, propagation speeds of disturbances, structural behavior of the rotor as well as unsteady wall pressure fields. The authors propose explanations for the different phenomena and possible influences of the rig on the in-stall behavior are discussed. Finally, an overview of the occurrence of the detected phenomena is given.

With the well-known Transonic Compressor Darmstadt (TCD) in operation since 1994, profound knowledge in designing and operating a sophisticated test-rig is available at the Institute of Gas Turbines and Aerospace Propulsion of TU Darmstadt. During this period, TCD has been subject to a vast number of redesigns within different measurement campaigns (see [1], [2], [3], [4], [5], [6], [7], [8]). To expand the capabilities and ensure a sustainable process of compressor research, a new test facility was designed and built by the institute. The new test rig Transonic Compressor Darmstadt 2 (TCD2) features increased power for higher pressure ratios and higher mass-flow, a state of the art control system, increased flexibility towards different compressor geometries and modern data acquisition hardware and software. Following the successful commissioning of the test-rig in March 2018, a first measurement campaign has been conducted. Early test results regarding aerodynamic performance and aeroelastic effects of the test compressor are presented together with a detailed overview of test-rig infrastructure and control systems as well as the test compressor and the measurement hardware.

An adaptive, swing-free trajectory planner for a gantry robot has been analytically developed and experimentally implemented on a commercial robot. A batch, nonlinear least square estimator (differential correction) is used to predict the initial conditions, mass, and frequency of the simply suspended object from a set of force sensor measurements.These parameters, in turn, are supplied to the swing-free trajectory planner to perform the maneuver.These algorithms have been implemented on a CIMCORP XR61001 gantry robot, and swing-free trajectories have been performed bv the robot using the adaptive trajector 3, planner.

Angularly accelerating a cantilevered rod which sags under gravity couples the out-of-plane dynamics of the flexible rod and causes oscillation in both the horizontal and vertical planes. A parameter-scheduled trajectory planner has been analytically developed and experimentally implemented on a commercial robot t o suppress the first mode of these vibrations during a horizontal angular move. A load was attached t o the tip of the rod and the resulting static, out-of-plane, hub torque was measured with a force-torque sensor. This torque was used to predict the period of the horizontal first mode of vibration of the payload (rod and attached load) from a nonlinear function in order to calculate (schedule) the appropriate control parameters for the angular move. This system has been implemented on a Cincinnati Milacron T3-786* robot, and vibration suppressed trajectories (which reduce the coupled residual vibrations by over 90%) have been performed by the robot for various payloads.