Abstract:

Influence of inclined bed channel on characteristic of flow for step broad–crested weirs was investigated experimentally. Discharge coefficient, water surface profile and Froude number were calculated experimentally.The results showed that water surface profiles were smooth and continues having a descending trend from the point of measurement taking the shape of the weir with a steep drop near the downstream face of the weir. Increasing effective head to crest height ratio (He/Y) and channel bed slope (So), increased the coefficient of discharge (CD) up to 5%. Also it was found. that for small values of (Fr2), the weir performance tends to the ideal .and with increase (Fr2), the discharge coefficient (CD) decrease for all weir models, because the discharge and the velocity heads increases. Empirical equation was developed on the basis of obtained results.

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