220 likes | 230 Views
Determination of Discharge by Entropy Concept in Natural River. Mehmet Ardiclioglu, Huseyin Bilgin, Onur Genc, Necati Ag i ralioglu. Outline. Introduction Discharge Calculation Fields Measurements 4. Result and Discussions 5. Conclusion. INTRODUCTION. W ater management,
E N D
Determination of Discharge by Entropy Concept in Natural River Mehmet Ardiclioglu, Huseyin Bilgin, Onur Genc, Necati Agiralioglu
Outline • Introduction • Discharge Calculation • Fields Measurements 4. Result and Discussions 5. Conclusion
INTRODUCTION • Water management, • Water resources planning, • Water supply, • Irrigation, • Flood control. • Design of hydraulic structures,
Discharge Calculation • Stage discharge rating curve • Empirical formulas • Velocity measurement • Entropy Methods
Stage discharge rating curve Q=c(h-a)b Q: Discharge, h: flow depth, c & b: coefficients derived for the relationship corresponding to the station a: Characteristics water level (m) corresponding to Q = 0
Manning’s equation Q; stream discharge, n ; Manning’s roughness parameter, A; channel cross-sectional area, R hydraulic radius (cross-sectional area/wetted perimeter) and S ;water slope. n0 ; the value of n for a straight, uniform, smooth channel in natural materials, n1 ; a value added to n0 to correct for the effect of surface irregularities, n2 ; a value for variations in shape and size of the channel cross-section, n3; a value for obstructions, n4 ; a value for vegetation and flow conditions, and m5 ;a correction factor for meandering of the channel.
Flow direction z bi V0,2H vj+1 hj aj V0,8H y vj Ai V0,6H Hi x Velocity-Area Method
Entropy Equation V; Cross-section mean velocity, vmax ; maximum velocity in the cross section, M ; entropy parameter.
Acoustic Doppler Velocimeters (ADV) FlowTracker Handheld ADV produced by SonTek • Velocity range: ±0.001to 4.0m/s • Velocity resolution: 0.0001m/s • Velocity accuracy: ±1% of measured velocity, ±0.25cm/s • Communication protocol: RS-232 • Power supply: 8AA batteries • Operating temperature: -20 to 50ºC
TURKEY Population : 67.803.927 - Census 2000Area : 779.452 km²The average altitude :1.132 m
Fields Measurements City Centrum SMS, DSI Measured station SIVAS YOZGAT Kizilirmak river Kizilirmak Basin Black Sea Yamula dam Sahsanem KAYSERI TURKEY Sarimsakli stream Mediterranean Sea
cross-section divided subsections Measuring cross-section
bed and water surface slopes measuring
Figure 5 Relative errors for different methods for discharge calculations
Conclusion • Velocity-area method, commonly used for discharge determination requires a great amount of time and effort. • Sampling procedure of velocity measurements in a river cross-section during high floods could be difficult and particularly dangerous. • Slope-area methods such as Manning equation includes indefinite parameters such as roughness coefficient n. • The ratio of the mean and maximum velocities of a cross-section, which characterize the flow pattern, approaches a constant. • The mean velocity can be obtained by the constant ratio and the maximum velocity. • The maximum velocity can be determined quickly by measuring only a few velocities from a single vertical axis.
Six different measurements shows that, slopes-area method gives relatively high errors (%9,37) for discharge at the measured cross-section on Sarimsakli river. • The two-point and 0,6-depth method produced very sensitive results but, require more measured data along the cross-sections. • Mean relative errors were calculated as %3,31 and %2,90 respectively for these methods. • But application of entropy methods is very easy for known entropy parameter M and this concept gives much closer discharge results compared to integrated ones. • Mean relative error for six different measurements was calculated as %3,23 between integrated discharge and entropy concept.