Scaling Laws of Droplet Coalescence: Theory and Numerical Simulation

<div>Two-dimensional plots of the velocity norm <svg height="11.439pt" id="M593" style="vertical-align:-2.15067pt" version="1.1" viewbox="-0.0498162 -9.28833 18.0678 11.439" width="18.0678pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M162 -163V703H102V-163H162ZM309 -163V703H249V-163H309Z"></path></g><g transform="matrix(.013,0,0,-0.013,5.343,0)"><path d="M542 56L520 58C483 62 478 72 478 124V449C455 445 422 441 387 438C351 435 316 432 287 431V402L318 395C345 389 350 383 350 336V93C328 71 306 65 279 65C245 65 211 88 211 153V298C211 356 211 407 214 449C187 445 151 441 118 438C84 435 53 432 28 431V402L51 395C77 388 83 383 83 337V130C83 42 131 -12 214 -12C245 -12 272 -1 300 18C322 31 333 41 350 55V-5L359 -12C389 -5 420 2 452 8C485 15 513 20 542 24V56Z"></path></g><g transform="matrix(.013,0,0,-0.013,12.558,0)"><path d="M162 -163V703H102V-163H162ZM309 -163V703H249V-163H309Z"></path></g></svg> of two interacting droplets of the same radius <svg height="11.8174pt" id="M594" style="vertical-align:-3.1815pt" version="1.1" viewbox="-0.0498162 -8.6359 41.1485 11.8174" width="41.1485pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M610 18C585 26 567 34 540 68C517 97 499 128 476 171C452 215 425 276 413 304C496 332 570 394 570 494C570 555 545 595 509 619S419 650 364 650H139L133 622C216 615 219 612 203 527L129 132C112 40 105 36 23 28L17 0H279L285 28C199 34 194 40 211 132L239 284H284C320 284 334 275 351 236C374 182 394 140 420 93C459 23 495 -1 592 -8H600L610 18ZM480 485C480 424 449 372 403 342C374 323 338 316 293 316H245L291 562C296 589 301 601 311 608S337 618 358 618C432 618 480 575 480 485Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,8.086,3.132)"><path d="M389 0V32C297 38 291 46 291 118V635C234 613 175 595 109 583V556L161 554C203 552 207 547 207 497V118C207 46 201 38 110 32V0H389Z"></path></g><g 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plane <svg height="12.6708pt" id="M595" style="vertical-align:-3.38247pt" version="1.1" viewbox="-0.0498162 -9.28833 39.3352 12.6708" width="39.3352pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M703 650H36V622C118 616 126 607 126 526V124C126 45 117 34 40 28V0H297V28C219 34 211 44 211 124V581C211 609 214 613 245 613H494C521 613 527 610 527 583V124C527 45 519 34 434 28V0H700V28C620 34 612 44 612 124V526C612 605 620 616 703 622V650Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,9.594,3.132)"><path d="M545 403C545 425 527 451 498 451C448 451 400 404 312 286L290 341C262 412 246 451 219 451C182 451 138 404 92 345L112 323C152 368 169 378 181 378C192 378 201 359 216 321L257 214C184 115 142 69 113 69C102 69 93 73 88 79S78 89 68 89C47 89 24 61 24 40C24 8 49 -12 75 -12C125 -12 175 31 271 175L312 64C330 15 357 -12 382 -12C421 -12 475 35 515 98L496 121C466 88 439 62 420 62C402 62 384 92 363 147L325 247C349 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410V442H293V410C332 402 337 394 323 371C311 351 295 324 274 293L227 371C213 393 218 402 252 410V442H16V410C70 402 80 391 108 344L196 199C166 159 140 123 115 95C81 54 61 43 7 32V0H196V32C156 41 150 53 167 81C182 105 199 138 219 166L269 79C287 49 283 38 245 32V0H494Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,30.666,3.132)"><path d="M357 391C357 416 325 451 270 451C241 451 179 431 146 400C109 365 97 334 97 307C97 248 143 213 196 180C250 146 261 123 261 101C261 75 237 40 190 40C153 40 110 72 86 109C81 116 68 119 55 112C37 102 24 87 24 66C24 30 85 -12 137 -12C229 -12 331 62 331 140C331 189 304 218 236 260C197 284 164 309 164 346C164 381 194 400 220 400C259 400 282 380 304 350C310 342 321 339 330 344C347 353 357 372 357 391Z"></path></g><g transform="matrix(.013,0,0,-0.013,34.644,0)"><path d="M275 270C275 450 212 609 64 710L45 686C145 604 203 442 203 270S147 -63 45 -147L64 -170C213 -68 275 89 275 270Z"></path></g></svg> at times <span class="nowrap"><svg height="8.55521pt" id="M596" style="vertical-align:-0.2063904pt" version="1.1" viewbox="-0.0498162 -8.34882 38.2628 8.55521" width="38.2628pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M324 430H196L233 583L223 592L145 529L120 430H54L29 396L31 388H111L56 126C33 15 54 -12 77 -12C137 -12 214 57 250 95L233 119C208 92 155 59 138 59C126 59 120 70 131 125L186 390L298 394L324 430Z"></path></g><g transform="matrix(.013,0,0,-0.013,8.065,0)"><path d="M535 323V373H52V323H535ZM535 138V188H52V138H535Z"></path></g><g transform="matrix(.013,0,0,-0.013,19.328,0)"><path d="M384 0V27C293 34 287 42 287 114V635C232 613 172 594 109 583V559L157 557C201 555 205 550 205 499V114C205 42 199 34 109 27V0H384Z"></path></g><g transform="matrix(.013,0,0,-0.013,25.568,0)"><path d="M241 635C89 635 35 457 35 312C35 153 89 -12 240 -12C390 -12 443 166 443 312C443 466 390 635 241 635ZM238 602C329 602 354 454 354 312C354 172 330 22 240 22C152 22 124 173 124 313S148 602 238 602Z"></path></g><g transform="matrix(.013,0,0,-0.013,31.808,0)"><path d="M241 635C89 635 35 457 35 312C35 153 89 -12 240 -12C390 -12 443 166 443 312C443 466 390 635 241 635ZM238 602C329 602 354 454 354 312C354 172 330 22 240 22C152 22 124 173 124 313S148 602 238 602Z"></path></g></svg>,</span> <svg height="8.55521pt" id="M597" style="vertical-align:-0.2063904pt" version="1.1" viewbox="-0.0498162 -8.34882 18.8898 8.55521" width="18.8898pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M384 0V27C293 34 287 42 287 114V635C232 613 172 594 109 583V559L157 557C201 555 205 550 205 499V114C205 42 199 34 109 27V0H384Z"></path></g><g transform="matrix(.013,0,0,-0.013,6.24,0)"><path d="M244 635C114 635 38 519 38 422C38 317 111 240 217 240C236 240 255 244 277 256L345 292C311 140 203 39 59 15L64 -15C89 -15 150 -5 204 17C339 72 440 202 440 386C440 521 368 635 244 635ZM228 602C326 602 352 479 352 390C352 370 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The solid lines stand for the iso-<svg height="11.439pt" id="M598" style="vertical-align:-2.15067pt" version="1.1" viewbox="-0.0498162 -9.28833 18.0678 11.439" width="18.0678pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M162 -163V703H102V-163H162ZM309 -163V703H249V-163H309Z"></path></g><g transform="matrix(.013,0,0,-0.013,5.343,0)"><path d="M542 56L520 58C483 62 478 72 478 124V449C455 445 422 441 387 438C351 435 316 432 287 431V402L318 395C345 389 350 383 350 336V93C328 71 306 65 279 65C245 65 211 88 211 153V298C211 356 211 407 214 449C187 445 151 441 118 438C84 435 53 432 28 431V402L51 395C77 388 83 383 83 337V130C83 42 131 -12 214 -12C245 -12 272 -1 300 18C322 31 333 41 350 55V-5L359 -12C389 -5 420 2 452 8C485 15 513 20 542 24V56Z"></path></g><g transform="matrix(.013,0,0,-0.013,12.558,0)"><path d="M162 -163V703H102V-163H162ZM309 -163V703H249V-163H309Z"></path></g></svg> contours.</div>

Advances in Mathematical Physics

fig12

Figure 12

Figure 12: Scaling Laws of Droplet Coalescence: Theory and Numerical Simulation 