Fadhel Abdulabbas Hassan Alshitali

In this research, a study was conducted experimentally to investigate the scour hole dimensions downstream the combined structures which consist from weir and gate. Twelve models have been designed and every model is formed from composite weir consists of two geometric shapes and three types of gates which are rectangular, semi-circular and triangular in shape, where multi factors were studied to find out the effect of changing geometry for both weir and gate, discharge flowing in the flume and particle size of bed material on the dimensions of scour hole. The experiments was conducted in a laboratory channel was constructed from blocks and concrete with length of 18 m, 1 m width and depth of 1 m, where the laboratory models were installed after 7 m from the main gate which is controlling the passage of water from the main reservoir into the flume. At the beginning, the calibration process was conducted to identify the actual discharge values that pass in the flume, then experiments were conducted to calculate the discharge coefficient for each model, which represents one of the studied factors within the dimensional analysis of the variables to derive the empirical formulas to calculate the dimensions of scour hole. Then the experiments were conducted in order to derive formulas to investigate the depth and length of the scour hole which formed in the sand floor spreading as a layer of 30 cm in thickness for a distance 4 m downstream combined structure. Two samples of sand were used in the experiments with different median size of particles ( d50), the first of 0.7 mm and the second of 1 mm. Using the dimensional analysis by π theorem and IBM SPSS 21 program, Four nonlinear relationships were derived to calculate the dimensionless scour depth (SD / d50) and another four nonlinear relationships calculates the dimensionless length of scour (SL / d50) depending on the laboratory results for each of the relative discharge (Qr), Froude number in terms of mean size of particle of bed material (Frd), non-dimensional difference head between upstream and downstream of combined structure (HD / d50), dimensionless distance between the lower edge of the weir and the upper edge of the gate (y3 / d50), dimensionless head over the crest of compound weir (h/d50) and the discharge coefficient (Cd), where the resulted determination coefficients (R2) from these relationships were good

In this paper, laboratory models were simulated by the software of Computational Fluid Dynamics (CFD) to develop a mathematical model that describes the relationship between the width of a gradual contraction in a rectangular channel under critical flow conditions within the zone of contraction. Four laboratory models with different widths of contraction: 14 cm, 16 cm, 18 cm, and 20 cm, were modeled in the CFD v18.2 program. A laboratory channel model having a cross-section of (0.3 m width * 0.6 m height) is also created. The length of contracted zone is chosen as 1 m, located at a distance of 0.75 m from the beginning of the channel, taking into account that the channel is gradually contracted at a 45o for all models. Nine values of discharges were applied to each model :20.5 l/s, 25 l/s, 30 l/s, 33.5 l/s, 38.6 l/s, 40.5 l/s, 45.2 l/s, 50 l/s and 57.6 l/s. Several measures of water depths were taken at different positions along the field of flow. The first position was at the upstream of contraction (y1); the second position was at the middle of the section of contraction where the critical flow occurs (yc); the third and fourth positions were located at the outlet of contraction when the hydraulic jump occurs (i.e. initial depth, yi and sequent depth, ys). Froude number (Fr) was measured for each case. All factors (y1, yc, yi, ys, and Fr) were processed to obtain non-linear coefficients using Buckingham's method (π – theorem) for dimensional analysis. Later, these coefficients were used in the software (SPSS v21) to derive a non-dimensional relationship between the non￾dimensional width (W/y1) and the other non-dimensional parameters. The developed relationship yielded a good coefficient of determination (R2).

Computational Fluid Dynamics (CFD) has been used to derive a mathematical model to relate the length of a gradual expansion (Le) with the others of hydraulic and geometric parameters of the flow in rectangular channels under supercritical flow conditions. Five models with different length of expansion 30 cm, 50 cm, 75 cm, 100 cm, and 125 cm were simulated in the CFD v18.2 software and verified by experimental data which have been measured into a laboratory flume. All models of CFD software were processed depending on k – epsilon viscous models while the mesh was built by adapting the multi-zone method. Five values of inlet velocity of flow were applied in the runs of the program to each model of 1.5 m/s, 1.6 m/s, 1.7 m/s, 1.8 m/s, and 2 m/s. Depths of water along the channel were measured in multi-section, before expansion, within expansion and after expansion. The results of CFD analysis showed that the minimum length of expansion to maintain the flow within supercritical regime was 0.35 m and the ratio of (Le/W) equal to 1.167. The results of the non-dimensional relationship were compared with the experimental results and the comparison showed a significant correlation where the highest percentage difference was 13.8 %. The coefficient of determination for this equation was 0.973.

This research is interested in finding a correlation between the amount of annual rainfall and some other hydrological factors such as relative humidity, temperatures and evaporation rates in the city of Najaf. The study is trying to find a mathematical model between the above-mentioned variables through the derivation of a nonlinear equation depending on the hydrological conditions of the holy city of Najaf and for data over 26 years (for the period from 1980 to 2005), where the differentiated correlation relationships were recorded between each of the annual rainfall on the one hand and rates relative humidity, temperatures and evaporation rates on the other. In this study, some of known statistical equations equation were used, such as coefficient of variation, to find the change in the amount of rainfall for this period and to determine the correlation between annual rainfall and other factors, Pearson's correlation coefficient (r) was used in addition the use of some statistical programs such as SPSS and EXCEL. The study demonstrated a relative correlation between the previous independent variables and the dependent variable (rainfall) depending on the change in the time period and the different climatic conditions in general.

The need to have a concrete with low absorption is very important in irrigation canals to keep water inside it without losses due to permeability since concrete is a porous material, therefore this study include the effect of integral waterproofing admixture type ADM-10 -1110 which is a liquid chemical polymer with organic compounds and using it individually with concrete and also using it with polymer modified concrete that contains styrene butadiene rubber polymers .this admixture make concrete with very low absorption and having a high mechanical properties . The ordinary mixes with 475 kg cement for each one cubic meter concrete show high increment in compressive and flexural strength by using integral waterproofing admixture(IWA) and less absorption , absorption decreased from 7.8% to 1.3 % , compressive strength increased from 36.9 MPa to 47.4 MPa and flexural strength increased from 2.7 MPa to 7.24 MPa , for polymer modified concrete, water absorption for it was very less , it decreased from 4.8% for reference mix of PMC to only 0.18% when adding 2.5% IWA by weight of cement.

In this research, an experimental work was conducted on models of broad crested weirs with different height of crest and different flow conditions, in sub – critical zone, to derive an equation to calculate the adequate height of a broad crested weir as a function of flow parameters such as initial depth, sequent depth, critical depth and Froude number due to the hydraulic jump will be generated downstream the weir. Five laboratory models were used in the experiments with crest heights of 30 cm, 35 cm, 40 cm, 45 cm, 50 cm and 55 cm. Each model will examined under different flow values (37 l/s , 31 l/s, 26 l/s, 11 l/s and 6 l/s.). All experiments were conducted in a laboratory flume with dimensions of (1 m * 1.15 m) in cross section and 18 m length. The flow conditions and geometric parameters of laboratory models were rearranged as a non-dimensional parameters using Л – theorem. The values of each Л will be scheduled and analyzed by the software of SPSS -21 to derive an empirical formula to calculate the non-dimensional height of crest. The value of the coefficient of determination (R2) resulted from the non-linear regression of data to derive the non-dimensional formula was very high.

The conference is held in coordination between the University of Technology in Iraq with the University of Menoufia in Egypt

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Sunday 8:30 – 9:30 Hydraulic Structures (4 th Class) 9:30 – 10:30 Hydraulic Structures (4 th Class) 10:3 – 11:30 Hydraulic Structures (4 th Class) 11:30 – 12:30 Hydraulic Structures (4 th Class) 12:30 – 1:30 Office Hours 1:30 – 2:30 Office Hours 2:30 – 3:30 Office Hours Monday 8:30 – 9:30 Engineering Project (4 th Class) 9:30 – 10:30 Engineering Project (4 th Class) 10:3 – 11:30 Engineering Project (4 th Class) 11:30 – 12:30 Engineering Project (4 th Class) 12:30 – 1:30 Other Committees 1:30 – 2:30 Other Committees 2:30 – 3:30 Office Hours Tuesday 8:30 – 9:30 Hydraulic Structures (4 th Class) 9:30 – 10:30 Hydraulic Structures (4 th Class) 10:3 – 11:30 Other Committees 11:30 – 12:30 Hydraulic Structures (4 th Class) 12:30 – 1:30 Hydraulic Structures (4 th Class) 1:30 – 2:30 Other Committees 2:30 – 3:30 Office Hours Wednesday 8:30 – 9:30 Office Hours 9:30 – 10:30 Office Hours 10:3 – 11:30 Office Hours 11:30 – 12:30 Office Hours 12:30 – 1:30 Office Hours 1:30 – 2:30 Office Hours 2:30 – 3:30 Office Hours Thursday 8:30 – 9:30 Scientific Research 9:30 – 10:30 Scientific Research 10:3 – 11:30 Scientific Research 11:30 – 12:30 Scientific Research 12:30 – 1:30 Scientific Research 1:30 – 2:30 Scientific Research 2:30 – 3:30 Scientific Research