Engineering topics

Muck, K. C.

Publications and source records attributed to Muck, K. C..

4 records

NASA NTRS1985

Structure of the wall pressure fluctuations in a shock-induced separated turbulent flow

This paper presents the results of an experimental study of the unsteady nature of a shock wave/turbulent boundary layer interaction. The interaction was generated using an unswept compression ramp. The incoming freestream Mach number was 2.9 and the flow was separated at the corner. An array of flush mounted miniature high frequency pressure transducers was used to make multi-channel measurements of the fluctuating wall pressure within the interaction. From the present results, an overall picture of the instantaneous structure of the unsteady shock system (as inferred from the wall pressure signals) can be constructed. The flow ahead of the corner can be considered as composed of two regions, namely the 'intermittent' region where there is essentially a single leading shock which exhibits significant streamwise 'flapping' and spanwise 'rippling', and the separated region where the flow experiences continuous compression.

Muck, K. C.↗

NASA NTRS1984

The behaviour of a compressible turbulent boundary layer under incipient separation conditions

This paper presents an experimental study of a turbulent boundary-layer/shock-wave interaction. The interaction was generated by a two-dimensional compression corner, and the flow was on the point of separating. Measurements were made using both normal and inclined hot wires, and the data include measurements of the longitudinal mass-flow fluctuation intensity and the mass-weighted Reynolds shear stress.

Muck, K. C.↗

NASA NTRS1983

Constant-temperature hot-wire anemometer practice in supersonic flows. I - The normal wire

The performance of a constant-temperature normal hot-wire in a supersonic flow is critically examined. It is shown that this instrument is inherently unsuitable for measuring turbulent temperature correlations because of the highly nonlinear response to temperature fluctuations, particularly at low overheat ratios. The instrument is therefore limited to measurements of mean and fluctuating mass-flow rates. Suitable calibration procedures, as well as the limits on spatial and temporal resolution are discussed, and corrections for mean stagnation temperature changes are suggested.

Smits, A. J.↗

NASA NTRS1983

Constant-temperature hot-wire anemometer practice in supersonic flows. II - The inclined wire

The performance of a constant-temperature inclined hot-wire in a supersonic flow is critically examined. It is shown that calibration techniques applicable to subsonic flow, such as the cosine cooling law cannot be used when the flow is supersonic. Calibration and measurement procedures appropriate to supersonic flow are suggested, together with the possible limits on their validity. Experimental results for different wires indicate that the sensitivities do not seem to depend on flow direction according to any simple correlation. When the sensitivity exhibits a strong dependence on flow direction, the wire should be discarded to avoid errors due to nonlinear effects.

Smits, A. J.↗