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Hydraulic head

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For relatively short pipe systems, with a relatively large number of bends and fittings, minor losses can easily exceed major losses. In design, minor losses are usually estimated from tables using coefficients or a simpler and less accurate reduction of minor losses to equivalent length of pipe, a
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This vector describes the direction of the groundwater flow, where negative values indicate flow along the dimension, and zero indicates 'no flow'. As with any other example in physics, energy must flow from high to low, which is why the flow is in the negative gradient. This vector can be used in
154:), and given information of the piezometer's elevation and screen depth. Hydraulic head can similarly be measured in a column of water using a standpipe piezometer by measuring the height of the water surface in the tube relative to a common datum. The hydraulic head can be used to determine a 1744:
example (first figure), where the hydraulic head is constant, there is no flow. However, if there is a difference in hydraulic head from the top to bottom due to draining from the bottom (second figure), the water will flow downward, due to the difference in head, also called the
1675:{\displaystyle \nabla h=\left({\frac {\partial h}{\partial x}},{\frac {\partial h}{\partial y}},{\frac {\partial h}{\partial z}}\right)={\frac {\partial h}{\partial x}}\mathbf {i} +{\frac {\partial h}{\partial y}}\mathbf {j} +{\frac {\partial h}{\partial z}}\mathbf {k} } 1784:
upon water levels observed in wells has been known for many years. The effect is a direct one, an increase in atmospheric pressure is an increase in load on the water in the aquifer, which increases the depth to water (lowers the water level elevation).
1105:, in particular). This means that the hydraulic head calculation is dependent on the density of the water within the piezometer. If one or more hydraulic head measurements are to be compared, they need to be standardized, usually to their 1824:, is divided into two main categories, "major losses" associated with energy loss per length of pipe, and "minor losses" associated with bends, fittings, valves, etc. The most common equation used to calculate major head losses is the 338: 1176: 1390: 983: 563: 723: 1248: 443: 764: 651: 1214: 456:, the internal molecular motion of a fluid that exerts a force on its container. It is equal to the pressure divided by the force/volume of the fluid in a gravitational field: 498: 247: 371: 830: 1026: 1115: 1056: 879: 1463: 1438: 1300: 1413: 1082: 1003: 909: 853: 671: 604: 1777:
through time, so this is often disregarded (contributing to large errors at locations where hydraulic gradients are low or the angle between wells is acute.)
214:. On Earth, additional height of fresh water adds a static pressure of about 9.8 kPa per meter (0.098 bar/m) or 0.433 psi per foot of water column height. 221:
of a pump is the maximum height (pressure) it can deliver. The capability of the pump at a certain RPM can be read from its Q-H curve (flow vs. height).
2143: 937: 2029: 186:, the total energy at a given point in a fluid is the kinetic energy associated with the speed of flow of the fluid, plus energy from 513:) is due to the frictional forces acting against a fluid's motion by the container. For a continuous medium, this is described by 1797: 531: 680: 2112: 398: 616: 1941: 1910: 770:, expressed as a length measurement. In a flowing fluid, it represents the energy of the fluid due to its bulk motion. 2168: 1995: 142:
It is usually measured as a liquid surface elevation, expressed in units of length, at the entrance (or bottom) of a
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first qualitatively observed these effects in the 17th century, and they were more rigorously described by the
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Fluid flows from the tank at the top to the basin at the bottom under the pressure of the hydraulic head.
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In an example with a 400 m deep piezometer, with an elevation of 1000 m, and a depth to water of 100 m:
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for other references which discuss hydraulic head in the context of hydrogeology, see that page's
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of a column of water at the base of the piezometer, and the elevation head is the relative
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method often used for shortcut calculations of pneumatic conveying lines pressure drop.
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between two or more hydraulic head measurements over the length of the flow path. For
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of water, which can vary depending on both the temperature and chemical composition (
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because their pumping characteristics tend to be independent of the fluid's density.
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hydraulic gradient can be calculated between two points with known head values as:
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is the flow path length between the two piezometers (length, usually in m or ft)
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in the fluid, plus energy from the height of the fluid relative to an arbitrary
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is the difference between two hydraulic heads (length, usually in m or ft), and
1171:{\displaystyle h_{\mathrm {fw} }=\psi {\frac {\rho }{\rho _{\mathrm {fw} }}}+z} 514: 241: 167: 136: 2246: 2221: 2206: 2079: 1786: 1294: 882: 448: 236: 1293:
and can be used to determine whether a reach is gaining or losing energy. A
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acting on a column of fluid. The elevation head is simply the elevation (
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fluid to the height of an equivalent static column of that fluid. From
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The hydraulic gradient can be expressed in vector notation, using the
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in the calculation of hydraulic head, it is more correct to use
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is the gauge pressure (Force per unit area, often Pa or psi),
978:{\displaystyle \psi ={\frac {P}{\gamma }}={\frac {P}{\rho g}}} 78:
Specific measurement of liquid pressure above a vertical datum
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is the fresh water head (Length, measured in m or ft), and
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of the liquid (Mass per unit volume, frequently kg¡m), and
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from an initial velocity of 0, a mass will have reached a
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while in a piped system head losses are described by the
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of fresh water (Mass per unit volume, typically in kg¡m)
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of the liquid (Force per unit volume, typically N¡m or
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In any real moving fluid, energy is dissipated due to
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to determine the flux of water in three dimensions.
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is the acceleration due to gravity. Rearranged as a
521:) to the gradient of the hydraulic head through the 773:The total hydraulic head of a fluid is composed of 120:, where the water level is above the ground surface 1674: 1457: 1432: 1407: 1384: 1242: 1208: 1170: 1076: 1050: 1020: 997: 977: 903: 873: 847: 824: 758: 717: 665: 645: 598: 557: 492: 437: 365: 332: 2144:List of conventional hydroelectric power stations 2244: 1934:Hydraulics of Open Channel Flow: An Introduction 859:in m or ft), also known as the piezometric head. 800:for incompressible fluids, can be expressed as: 92:Available difference in hydraulic head across a 1903:Flow of Industrial Fluids: Theory and Equations 1971:"Pipe equivalent length (Pneumatic conveying)" 1896: 1894: 1736:The distribution of hydraulic head through an 2106: 2023: 1740:determines where groundwater will flow. In a 100:due to turbines, wall friction and turbulence 1924: 1922: 1960:, Section 3.7 (Fourth edition) McGraw-Hill 1891: 1828:. Older, more empirical approaches are the 911:is the elevation at the piezometer bottom ( 2113: 2099: 2030: 2016: 1415:is the hydraulic gradient (dimensionless), 1283:or discharge. It also has applications in 1088:(velocity change per unit time, often m¡s) 1919: 66:Learn how and when to remove this message 1279:, since it determines the quantity of a 231:There are generally four types of head: 111: 103: 87: 29:This article includes a list of general 1928: 1800:(USDA)) using air flow models in 1907. 1798:United States Department of Agriculture 1752: 934:The pressure head can be expressed as: 558:{\displaystyle \mathbf {q} =-K\nabla h} 2245: 1900: 1097:The pressure head is dependent on the 781:. The pressure head is the equivalent 718:{\displaystyle h={\frac {v^{2}}{2g}}.} 2094: 2011: 1816:dissipates even more energy for high 1258: 1243:{\displaystyle \rho _{\mathrm {fw} }} 1757:Even though it is convention to use 438:{\displaystyle h_{e}=\rho gh/\rho g} 15: 1092: 759:{\displaystyle {\frac {v^{2}}{2g}}} 646:{\displaystyle v={\sqrt {{2g}{h}}}} 13: 1988:Dynamics of Fluids in Porous Media 1658: 1650: 1630: 1622: 1602: 1594: 1574: 1566: 1551: 1543: 1528: 1520: 1503: 1376: 1373: 1370: 1367: 1364: 1361: 1234: 1231: 1200: 1197: 1154: 1151: 1128: 1125: 549: 387:is due to the fluid's weight, the 35:it lacks sufficient corresponding 14: 2289: 2169:Run-of-the-river hydroelectricity 1698: 1476:. This requires a hydraulic head 1209:{\displaystyle h_{\mathrm {fw} }} 206:is the density of the fluid, and 2177: 1820:flows. This dissipation, called 1726: 1717: 1668: 1640: 1612: 536: 517:which relates volume flow rate ( 20: 2149:Pumped-storage hydroelectricity 116:Measuring hydraulic head in an 2120: 1963: 1950: 1702: 1109:, which can be calculated as: 792:in terms of an elevation. The 510: 493:{\displaystyle h_{p}=p/\rho g} 174:is a concept that relates the 97: 1: 1980: 1704:Relation between heads for a 577: 224:Head is useful in specifying 161: 131:is a specific measurement of 1803: 1496:, this can be expressed as: 158:between two or more points. 7: 1956:Streeter, Victor L. (1958) 1916:, 410 pages. See pp. 43–44. 1843: 796:, a simplified form of the 366:{\displaystyle \rho gh_{v}} 240:is due to the bulk motion ( 10: 2294: 1780:The effects of changes in 1773:are not available at each 1287:where it is also known as 1086:gravitational acceleration 212:gravitational acceleration 80: 2186: 2175: 2128: 2050: 1936:, Butterworth–Heinemann, 1860:Minor losses in pipe flow 825:{\displaystyle h=\psi +z} 567:Hagen–Poiseuille equation 1901:Mulley, Raymond (2004), 1885: 1275:, it is also called the 81:Not to be confused with 2003:further reading section 1947:, 650 pages. See p. 22. 1830:Hazen–Williams equation 1826:Darcy–Weisbach equation 1021:{\displaystyle \gamma } 855:is the hydraulic head ( 50:more precise citations. 2212:Gorlov helical turbine 2060:hydraulic conductivity 1693:hydraulic conductivity 1676: 1492:for open channels. In 1459: 1434: 1409: 1386: 1244: 1210: 1172: 1078: 1052: 1022: 999: 979: 905: 875: 849: 826: 760: 719: 667: 647: 600: 559: 523:hydraulic conductivity 494: 439: 367: 334: 121: 109: 101: 1880:Hydraulic accumulator 1850:Borda–Carnot equation 1677: 1494:Cartesian coordinates 1460: 1435: 1410: 1387: 1245: 1211: 1173: 1079: 1053: 1051:{\displaystyle \rho } 1023: 1000: 980: 906: 876: 874:{\displaystyle \psi } 850: 827: 761: 720: 668: 648: 601: 560: 495: 440: 368: 335: 184:Bernoulli's principle 115: 107: 91: 1782:atmospheric pressure 1767:atmospheric pressure 1753:Atmospheric pressure 1500: 1446: 1421: 1399: 1301: 1222: 1188: 1116: 1068: 1042: 1012: 989: 938: 895: 865: 839: 804: 731: 681: 657: 617: 590: 571:Bernoulli’s equation 532: 460: 399: 344: 248: 2042:properties used in 1771:barometric pressure 1713: 1484:for groundwater or 798:Bernoulli principle 389:gravitational force 196:gravitational field 2227:Cross-flow turbine 1865:Total dynamic head 1765:(gauge pressure + 1747:hydraulic gradient 1703: 1672: 1458:{\displaystyle dl} 1455: 1433:{\displaystyle dh} 1430: 1405: 1382: 1265:hydraulic gradient 1259:Hydraulic gradient 1240: 1206: 1168: 1074: 1048: 1018: 995: 975: 901: 871: 845: 822: 756: 715: 663: 643: 596: 555: 490: 435: 363: 330: 274: 156:hydraulic gradient 122: 110: 102: 2240: 2239: 2088: 2087: 1870:Stage (hydrology) 1796:(working for the 1763:absolute pressure 1734: 1733: 1683:conjunction with 1665: 1637: 1609: 1581: 1558: 1535: 1408:{\displaystyle i} 1380: 1328: 1285:open-channel flow 1160: 1077:{\displaystyle g} 998:{\displaystyle P} 973: 955: 904:{\displaystyle z} 848:{\displaystyle h} 754: 710: 666:{\displaystyle g} 641: 599:{\displaystyle h} 586:through a height 379:irrotational flow 328: 311: 273: 226:centrifugal pumps 94:hydroelectric dam 76: 75: 68: 2285: 2188:Hydroelectricity 2181: 2130:Hydroelectricity 2115: 2108: 2101: 2092: 2091: 2032: 2025: 2018: 2009: 2008: 1975: 1974: 1967: 1961: 1954: 1948: 1946: 1926: 1917: 1915: 1898: 1875:Head (hydrology) 1855:Dynamic pressure 1794:Edgar Buckingham 1730: 1721: 1714: 1681: 1679: 1678: 1673: 1671: 1666: 1664: 1656: 1648: 1643: 1638: 1636: 1628: 1620: 1615: 1610: 1608: 1600: 1592: 1587: 1583: 1582: 1580: 1572: 1564: 1559: 1557: 1549: 1541: 1536: 1534: 1526: 1518: 1464: 1462: 1461: 1456: 1439: 1437: 1436: 1431: 1414: 1412: 1411: 1406: 1391: 1389: 1388: 1383: 1381: 1379: 1359: 1358: 1357: 1345: 1344: 1334: 1329: 1327: 1319: 1311: 1249: 1247: 1246: 1241: 1239: 1238: 1237: 1215: 1213: 1212: 1207: 1205: 1204: 1203: 1177: 1175: 1174: 1169: 1161: 1159: 1158: 1157: 1141: 1133: 1132: 1131: 1107:fresh water head 1093:Fresh water head 1083: 1081: 1080: 1075: 1057: 1055: 1054: 1049: 1027: 1025: 1024: 1019: 1004: 1002: 1001: 996: 984: 982: 981: 976: 974: 972: 961: 956: 948: 910: 908: 907: 902: 889:in m or ft), and 880: 878: 877: 872: 854: 852: 851: 846: 831: 829: 828: 823: 790:potential energy 765: 763: 762: 757: 755: 753: 745: 744: 735: 724: 722: 721: 716: 711: 709: 701: 700: 691: 672: 670: 669: 664: 652: 650: 649: 644: 642: 640: 635: 627: 605: 603: 602: 597: 564: 562: 561: 556: 539: 499: 497: 496: 491: 483: 472: 471: 444: 442: 441: 436: 428: 411: 410: 375:dynamic pressure 373:is equal to the 372: 370: 369: 364: 362: 361: 339: 337: 336: 331: 329: 324: 323: 314: 312: 304: 293: 288: 287: 275: 266: 260: 259: 129:piezometric head 118:artesian aquifer 83:Head (hydrology) 71: 64: 60: 57: 51: 46:this article by 37:inline citations 24: 23: 16: 2293: 2292: 2288: 2287: 2286: 2284: 2283: 2282: 2243: 2242: 2241: 2236: 2197:Francis turbine 2182: 2173: 2124: 2119: 2089: 2084: 2046: 2036: 1986:Bear, J. 1972. 1983: 1978: 1969: 1968: 1964: 1958:Fluid Mechanics 1955: 1951: 1944: 1930:Chanson, Hubert 1927: 1920: 1913: 1899: 1892: 1888: 1846: 1818:Reynolds number 1806: 1755: 1701: 1667: 1657: 1649: 1647: 1639: 1629: 1621: 1619: 1611: 1601: 1593: 1591: 1573: 1565: 1563: 1550: 1542: 1540: 1527: 1519: 1517: 1516: 1512: 1501: 1498: 1497: 1447: 1444: 1443: 1422: 1419: 1418: 1400: 1397: 1396: 1360: 1353: 1349: 1340: 1336: 1335: 1333: 1320: 1312: 1310: 1302: 1299: 1298: 1290:stream gradient 1269:vector gradient 1261: 1230: 1229: 1225: 1223: 1220: 1219: 1196: 1195: 1191: 1189: 1186: 1185: 1150: 1149: 1145: 1140: 1124: 1123: 1119: 1117: 1114: 1113: 1095: 1069: 1066: 1065: 1043: 1040: 1039: 1013: 1010: 1009: 990: 987: 986: 965: 960: 947: 939: 936: 935: 896: 893: 892: 866: 863: 862: 840: 837: 836: 805: 802: 801: 746: 740: 736: 734: 732: 729: 728: 702: 696: 692: 690: 682: 679: 678: 658: 655: 654: 636: 628: 626: 618: 615: 614: 591: 588: 587: 580: 535: 533: 530: 529: 503:Resistance head 479: 467: 463: 461: 458: 457: 454:static pressure 424: 406: 402: 400: 397: 396: 357: 353: 345: 342: 341: 319: 315: 313: 303: 289: 283: 279: 264: 255: 251: 249: 246: 245: 188:static pressure 164: 133:liquid pressure 86: 79: 72: 61: 55: 52: 42:Please help to 41: 25: 21: 12: 11: 5: 2291: 2281: 2280: 2275: 2270: 2268:Fluid dynamics 2265: 2260: 2255: 2238: 2237: 2235: 2234: 2229: 2224: 2219: 2214: 2209: 2204: 2202:Kaplan turbine 2199: 2193: 2191: 2184: 2183: 2176: 2174: 2172: 2171: 2166: 2161: 2156: 2151: 2146: 2141: 2135: 2133: 2126: 2125: 2118: 2117: 2110: 2103: 2095: 2086: 2085: 2083: 2082: 2077: 2072: 2067: 2062: 2057: 2055:hydraulic head 2051: 2048: 2047: 2035: 2034: 2027: 2020: 2012: 2006: 2005: 1999: 1982: 1979: 1977: 1976: 1962: 1949: 1943:978-0750659789 1942: 1918: 1912:978-0849327674 1911: 1889: 1887: 1884: 1883: 1882: 1877: 1872: 1867: 1862: 1857: 1852: 1845: 1842: 1834:Prony equation 1805: 1802: 1791:soil physicist 1759:gauge pressure 1754: 1751: 1732: 1731: 1723: 1722: 1700: 1699:In groundwater 1697: 1670: 1663: 1660: 1655: 1652: 1646: 1642: 1635: 1632: 1627: 1624: 1618: 1614: 1607: 1604: 1599: 1596: 1590: 1586: 1579: 1576: 1571: 1568: 1562: 1556: 1553: 1548: 1545: 1539: 1533: 1530: 1525: 1522: 1515: 1511: 1508: 1505: 1467: 1466: 1454: 1451: 1441: 1429: 1426: 1416: 1404: 1378: 1375: 1372: 1369: 1366: 1363: 1356: 1352: 1348: 1343: 1339: 1332: 1326: 1323: 1318: 1315: 1309: 1306: 1260: 1257: 1256: 1255: 1236: 1233: 1228: 1217: 1202: 1199: 1194: 1179: 1178: 1167: 1164: 1156: 1153: 1148: 1144: 1139: 1136: 1130: 1127: 1122: 1094: 1091: 1090: 1089: 1073: 1063: 1047: 1037: 1017: 994: 971: 968: 964: 959: 954: 951: 946: 943: 917: 916: 900: 890: 870: 860: 844: 821: 818: 815: 812: 809: 779:elevation head 766:is called the 752: 749: 743: 739: 714: 708: 705: 699: 695: 689: 686: 662: 639: 634: 631: 625: 622: 595: 579: 576: 575: 574: 554: 551: 548: 545: 542: 538: 500: 489: 486: 482: 478: 475: 470: 466: 452:is due to the 445: 434: 431: 427: 423: 420: 417: 414: 409: 405: 385:Elevation head 382: 360: 356: 352: 349: 327: 322: 318: 310: 307: 302: 299: 296: 292: 286: 282: 278: 272: 269: 263: 258: 254: 242:kinetic energy 180:incompressible 168:fluid dynamics 163: 160: 137:vertical datum 125:Hydraulic head 77: 74: 73: 28: 26: 19: 9: 6: 4: 3: 2: 2290: 2279: 2276: 2274: 2271: 2269: 2266: 2264: 2261: 2259: 2256: 2254: 2251: 2250: 2248: 2233: 2230: 2228: 2225: 2223: 2222:Turgo turbine 2220: 2218: 2215: 2213: 2210: 2208: 2207:Tyson turbine 2205: 2203: 2200: 2198: 2195: 2194: 2192: 2189: 2185: 2180: 2170: 2167: 2165: 2162: 2160: 2157: 2155: 2152: 2150: 2147: 2145: 2142: 2140: 2137: 2136: 2134: 2131: 2127: 2123: 2116: 2111: 2109: 2104: 2102: 2097: 2096: 2093: 2081: 2080:water content 2078: 2076: 2073: 2071: 2068: 2066: 2063: 2061: 2058: 2056: 2053: 2052: 2049: 2045: 2041: 2033: 2028: 2026: 2021: 2019: 2014: 2013: 2010: 2004: 2000: 1997: 1996:0-486-65675-6 1993: 1989: 1985: 1984: 1972: 1966: 1959: 1953: 1945: 1939: 1935: 1931: 1925: 1923: 1914: 1908: 1905:, CRC Press, 1904: 1897: 1895: 1890: 1881: 1878: 1876: 1873: 1871: 1868: 1866: 1863: 1861: 1858: 1856: 1853: 1851: 1848: 1847: 1841: 1837: 1835: 1831: 1827: 1823: 1819: 1815: 1811: 1801: 1799: 1795: 1792: 1788: 1783: 1778: 1776: 1772: 1768: 1764: 1760: 1750: 1748: 1743: 1739: 1729: 1725: 1724: 1720: 1716: 1715: 1711: 1710:downward flow 1707: 1696: 1694: 1690: 1686: 1661: 1653: 1644: 1633: 1625: 1616: 1605: 1597: 1588: 1584: 1577: 1569: 1560: 1554: 1546: 1537: 1531: 1523: 1513: 1509: 1506: 1495: 1491: 1487: 1486:standard step 1483: 1479: 1475: 1472: 1452: 1449: 1442: 1427: 1424: 1417: 1402: 1395: 1394: 1393: 1354: 1350: 1346: 1341: 1337: 1330: 1324: 1321: 1316: 1313: 1307: 1304: 1296: 1295:dimensionless 1292: 1291: 1286: 1282: 1278: 1274: 1270: 1266: 1253: 1226: 1218: 1192: 1184: 1183: 1182: 1165: 1162: 1146: 1142: 1137: 1134: 1120: 1112: 1111: 1110: 1108: 1104: 1100: 1087: 1071: 1064: 1061: 1045: 1038: 1035: 1031: 1015: 1008: 1007: 1006: 992: 969: 966: 962: 957: 952: 949: 944: 941: 932: 930: 927:= 300 m, and 926: 922: 914: 898: 891: 888: 884: 883:pressure head 868: 861: 858: 842: 835: 834: 833: 819: 816: 813: 810: 807: 799: 795: 794:head equation 791: 787: 784: 780: 776: 775:pressure head 771: 769: 768:velocity head 750: 747: 741: 737: 725: 712: 706: 703: 697: 693: 687: 684: 676: 660: 637: 632: 629: 623: 620: 613: 609: 593: 585: 572: 568: 552: 546: 543: 540: 527: 524: 520: 516: 512: 508: 507:friction head 504: 501: 487: 484: 480: 476: 473: 468: 464: 455: 451: 450: 449:Pressure head 446: 432: 429: 425: 421: 418: 415: 412: 407: 403: 394: 390: 386: 383: 380: 376: 358: 354: 350: 347: 325: 320: 316: 308: 305: 300: 297: 294: 290: 284: 280: 276: 270: 267: 261: 256: 252: 244:) of a fluid. 243: 239: 238: 237:Velocity head 234: 233: 232: 229: 227: 222: 220: 215: 213: 209: 205: 201: 197: 193: 189: 185: 181: 177: 173: 169: 159: 157: 153: 149: 145: 140: 138: 134: 130: 126: 119: 114: 106: 99: 95: 90: 84: 70: 67: 59: 49: 45: 39: 38: 32: 27: 18: 17: 2217:Pelton wheel 2070:permeability 2054: 2044:hydrogeology 1987: 1965: 1957: 1952: 1933: 1902: 1838: 1821: 1807: 1779: 1756: 1746: 1735: 1709: 1705: 1468: 1288: 1276: 1264: 1262: 1180: 1106: 1096: 933: 928: 924: 920: 918: 793: 778: 774: 772: 767: 726: 674: 584:free falling 581: 525: 518: 506: 502: 447: 392: 384: 235: 230: 223: 218: 216: 207: 203: 199: 198:is equal to 171: 165: 155: 141: 128: 124: 123: 62: 53: 34: 2273:Water wells 2232:Water wheel 2159:Micro hydro 2154:Small hydro 2065:storativity 1742:hydrostatic 1708:case and a 1706:hydrostatic 1685:Darcy's law 1277:Darcy slope 1273:groundwater 1030:unit weight 915:in m or ft) 515:Darcy's law 219:static head 98:head losses 48:introducing 2247:Categories 2164:Pico hydro 2132:generation 2122:Hydropower 1981:References 1814:turbulence 1281:Darcy flux 578:Components 340:Note that 162:Definition 152:water well 144:piezometer 56:April 2020 31:references 2263:Hydrology 2190:equipment 2038:Physical 1990:, Dover. 1822:head loss 1804:Head loss 1659:∂ 1651:∂ 1631:∂ 1623:∂ 1603:∂ 1595:∂ 1575:∂ 1567:∂ 1552:∂ 1544:∂ 1529:∂ 1521:∂ 1504:∇ 1347:− 1227:ρ 1147:ρ 1143:ρ 1138:ψ 1046:ρ 1016:γ 967:ρ 953:γ 942:ψ 931:= 900 m. 923:= 600 m, 869:ψ 814:ψ 727:The term 550:∇ 544:− 511:Head Loss 485:ρ 430:ρ 416:ρ 348:ρ 295:ρ 277:ρ 96:, before 2278:Pressure 2253:Aquifers 2075:porosity 1932:(2004), 1844:See also 1832:and the 1810:friction 1474:operator 1103:salinity 786:pressure 146:. In an 135:above a 2040:aquifer 1738:aquifer 1490:HEC-RAS 1482:MODFLOW 1252:density 1250:is the 1099:density 1084:is the 1060:density 1058:is the 1028:is the 881:is the 210:is the 200:ρg 148:aquifer 44:improve 1994:  1940:  1909:  1787:Pascal 1712:case. 1689:tensor 1687:and a 1392:where 1181:where 985:where 913:Length 887:Length 857:Length 832:where 653:where 608:vacuum 582:After 204:ρ 202:where 178:in an 176:energy 33:, but 2258:Water 1886:Notes 1478:field 1267:is a 1036:/ft), 783:gauge 612:speed 606:in a 192:datum 1992:ISBN 1938:ISBN 1907:ISBN 1775:well 1263:The 777:and 675:head 569:and 505:(or 377:for 217:The 172:head 2139:Dam 1691:of 1488:or 1471:del 1034:lbf 509:or 166:In 127:or 2249:: 1921:^ 1893:^ 1836:. 1812:; 1749:. 677:: 528:: 170:, 139:. 2114:e 2107:t 2100:v 2031:e 2024:t 2017:v 1998:. 1973:. 1669:k 1662:z 1654:h 1645:+ 1641:j 1634:y 1626:h 1617:+ 1613:i 1606:x 1598:h 1589:= 1585:) 1578:z 1570:h 1561:, 1555:y 1547:h 1538:, 1532:x 1524:h 1514:( 1510:= 1507:h 1453:l 1450:d 1428:h 1425:d 1403:i 1377:h 1374:t 1371:g 1368:n 1365:e 1362:l 1355:1 1351:h 1342:2 1338:h 1331:= 1325:l 1322:d 1317:h 1314:d 1308:= 1305:i 1235:w 1232:f 1201:w 1198:f 1193:h 1166:z 1163:+ 1155:w 1152:f 1135:= 1129:w 1126:f 1121:h 1072:g 993:P 970:g 963:P 958:= 950:P 945:= 929:h 925:ψ 921:z 899:z 843:h 820:z 817:+ 811:= 808:h 751:g 748:2 742:2 738:v 713:. 707:g 704:2 698:2 694:v 688:= 685:h 661:g 638:h 633:g 630:2 624:= 621:v 594:h 573:. 553:h 547:K 541:= 537:q 526:K 519:q 488:g 481:/ 477:p 474:= 469:p 465:h 433:g 426:/ 422:h 419:g 413:= 408:e 404:h 393:h 381:. 359:v 355:h 351:g 326:g 321:2 317:v 309:2 306:1 301:= 298:g 291:/ 285:2 281:v 271:2 268:1 262:= 257:v 253:h 208:g 85:. 69:) 63:( 58:) 54:( 40:.

Index

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Head (hydrology)

hydroelectric dam
head losses


artesian aquifer
liquid pressure
vertical datum
piezometer
aquifer
water well
fluid dynamics
energy
incompressible
Bernoulli's principle
static pressure
datum
gravitational field
gravitational acceleration
centrifugal pumps
Velocity head
kinetic energy
dynamic pressure
irrotational flow

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