Analysis of Flow Evolution and Thermal Instabilities in the Near-Nozzle Region of a Free Plane Laminar Jet

<div>Stability diagram, represented by the critical Reynolds number as a function of the temperature difference <svg height="15.0979pt" id="M167" style="vertical-align:-5.75998pt" version="1.1" viewbox="-0.0498162 -9.33792 26.2549 15.0979" width="26.2549pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.0135,0,0,-0.0135,0,0)"><path d="M600 0V24L339 665L311 657L43 24V0H600ZM497 50H107L303 539L497 50Z" id="g113-133"></path><glyph.data ascent="3473" descent="-2876" horiz-adv-x="641" vert-adv-y="641"></glyph.data></g><g transform="matrix(.0135,0,0,-0.0135,8.678,0)"><path d="M620 675H597C578 656 570 650 541 650H144C112 650 104 653 94 675H72C59 618 42 552 23 493L53 491C71 534 88 564 105 585C124 608 144 615 238 615H290L197 121C182 40 174 34 88 28L82 0H361L367 28C275 34 266 38 281 121L374 615H441C522 615 543 608 553 583C562 560 566 531 565 493L597 494C603 551 612 629 620 675Z" id="g113-85"></path><glyph.data ascent="3473" descent="-2876" horiz-adv-x="637" vert-adv-y="637"></glyph.data></g><g transform="matrix(.0095,0,0,-0.0095,16.157,3.264)"><path d="M135 536C163 536 185 560 185 587C185 617 163 639 136 639C108 639 85 617 85 587C85 560 108 536 135 536ZM34 389C96 380 101 376 101 308V113C101 22 99 -37 93 -80C87 -114 80 -137 68 -152C54 -170 28 -182 -5 -190C-19 -193 -26 -200 -26 -213C-26 -237 -3 -257 10 -257C18 -257 26 -253 36 -246C59 -226 122 -150 157 -50C176 3 180 46 180 111V451C137 433 86 420 34 412V389Z" id="g190-107"></path><glyph.data ascent="989" descent="-360" horiz-adv-x="256" vert-adv-y="256"></glyph.data></g><g transform="matrix(.0095,0,0,-0.0095,18.632,3.264)"><path d="M380 106C343 72 306 56 265 56C195 56 116 112 115 248C235 252 361 262 377 265C396 269 400 277 400 297C400 374 333 449 250 449H249C198 449 144 421 103 376S37 269 37 201C37 88 109 -12 232 -12C263 -12 332 6 395 84L380 106ZM225 412C281 412 315 364 314 312C314 297 308 292 290 292C232 290 176 289 120 289C135 370 180 412 225 412Z" id="g190-102"></path><glyph.data ascent="989" descent="-360" horiz-adv-x="425" vert-adv-y="425"></glyph.data></g><g transform="matrix(.0095,0,0,-0.0095,22.663,3.264)"><path d="M298 36L289 62C276 55 253 45 228 45C202 45 169 60 169 141V397H276C289 405 292 426 282 437H169V574L155 576L90 509V437H45L17 408L21 397H90V107C90 28 125 -12 188 -12C198 -12 213 -8 230 1L298 36Z" id="g190-117"></path><glyph.data ascent="989" descent="-360" horiz-adv-x="305" vert-adv-y="305"></glyph.data></g></svg>, where <svg height="15.4379pt" id="M168" style="vertical-align:-5.759999pt" version="1.1" viewbox="-0.0498162 -9.6779 85.0431 15.4379" width="85.0431pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.0135,0,0,-0.0135,0,0)"><path d="M631 18C609 24 585 35 559 65C534 91 514 117 478 169C448 214 406 281 389 313C462 346 516 399 516 485C516 545 490 590 449 616C412 641 363 650 290 650H42V622C120 615 128 612 128 527V125C128 40 120 34 38 28V0H300V28C221 34 212 40 212 125V284H244C295 284 312 272 329 244C359 195 395 133 430 84C475 19 516 -3 592 -7C603 -8 615 -8 627 -8L631 18ZM212 316V563C212 591 215 602 223 607C231 613 248 617 277 617C352 617 423 577 423 469C423 415 407 375 368 345C343 324 310 316 260 316H212Z" id="g121-80"></path><glyph.data ascent="989" descent="-360" horiz-adv-x="621" vert-adv-y="621"></glyph.data></g><g transform="matrix(.0135,0,0,-0.0135,8.59,0)"><path d="M380 106C343 72 306 56 265 56C195 56 116 112 115 248C235 252 361 262 377 265C396 269 400 277 400 297C400 374 333 449 250 449H249C198 449 144 421 103 376S37 269 37 201C37 88 109 -12 232 -12C263 -12 332 6 395 84L380 106ZM225 412C281 412 315 364 314 312C314 297 308 292 290 292C232 290 176 289 120 289C135 370 180 412 225 412Z" id="g121-99"></path><glyph.data ascent="989" descent="-360" horiz-adv-x="425" vert-adv-y="425"></glyph.data></g><g transform="matrix(.0135,0,0,-0.0135,18.186,0)"><path d="M535 323V373H52V323H535ZM535 138V188H52V138H535Z" id="g117-34"></path><glyph.data ascent="3473" descent="-2876" horiz-adv-x="587" vert-adv-y="587"></glyph.data></g><g transform="matrix(.0135,0,0,-0.0135,29.924,0)"><path d="M600 0V24L339 665L311 657L43 24V0H600ZM497 50H107L303 539L497 50Z" id="g113-133"></path><glyph.data ascent="3473" descent="-2876" horiz-adv-x="641" vert-adv-y="641"></glyph.data></g><g transform="matrix(.0135,0,0,-0.0135,38.602,0)"><path d="M715 650H476L470 622C550 619 562 610 562 570C562 536 553 481 535 384L523 321C485 121 408 37 283 37C178 37 99 109 134 297L178 532C193 612 199 616 278 622L284 650H29L23 622C105 616 109 609 94 532L48 291C23 160 51 83 98 40C143 -1 202 -16 260 -16C321 -16 387 3 439 49C509 111 542 204 563 312L577 384C595 479 608 533 619 569C629 603 637 620 709 622L715 650Z" id="g113-86"></path><glyph.data ascent="3473" descent="-2876" horiz-adv-x="727" vert-adv-y="727"></glyph.data></g><g transform="matrix(.0095,0,0,-0.0095,47.571,3.264)"><path d="M135 536C163 536 185 560 185 587C185 617 163 639 136 639C108 639 85 617 85 587C85 560 108 536 135 536ZM34 389C96 380 101 376 101 308V113C101 22 99 -37 93 -80C87 -114 80 -137 68 -152C54 -170 28 -182 -5 -190C-19 -193 -26 -200 -26 -213C-26 -237 -3 -257 10 -257C18 -257 26 -253 36 -246C59 -226 122 -150 157 -50C176 3 180 46 180 111V451C137 433 86 420 34 412V389Z" id="g190-107"></path><glyph.data ascent="989" descent="-360" horiz-adv-x="256" vert-adv-y="256"></glyph.data></g><g transform="matrix(.0095,0,0,-0.0095,50.046,3.264)"><path d="M380 106C343 72 306 56 265 56C195 56 116 112 115 248C235 252 361 262 377 265C396 269 400 277 400 297C400 374 333 449 250 449H249C198 449 144 421 103 376S37 269 37 201C37 88 109 -12 232 -12C263 -12 332 6 395 84L380 106ZM225 412C281 412 315 364 314 312C314 297 308 292 290 292C232 290 176 289 120 289C135 370 180 412 225 412Z" id="g190-102"></path><glyph.data ascent="989" descent="-360" horiz-adv-x="425" vert-adv-y="425"></glyph.data></g><g transform="matrix(.0095,0,0,-0.0095,54.077,3.264)"><path d="M298 36L289 62C276 55 253 45 228 45C202 45 169 60 169 141V397H276C289 405 292 426 282 437H169V574L155 576L90 509V437H45L17 408L21 397H90V107C90 28 125 -12 188 -12C198 -12 213 -8 230 1L298 36Z" id="g190-117"></path><glyph.data ascent="989" descent="-360" horiz-adv-x="305" vert-adv-y="305"></glyph.data></g><g transform="matrix(.0135,0,0,-0.0135,57.503,0)"><path d="M391 364C391 409 353 448 295 448C249 448 198 426 152 393C65 331 23 225 23 139C23 14 96 -12 146 -12C198 -12 280 9 367 101L351 124C300 78 242 48 194 48C129 48 109 107 109 162V191C208 213 391 266 391 364ZM313 350C313 305 268 261 113 223C132 334 187 381 217 398C227 404 244 405 261 405C290 405 313 385 313 350Z" id="g113-102"></path><glyph.data ascent="3473" descent="-2876" horiz-adv-x="414" vert-adv-y="414"></glyph.data></g><g transform="matrix(.0135,0,0,-0.0135,63.112,0)"><path d="M368 703H309L44 -163H104L368 703Z" id="g113-48"></path><glyph.data ascent="3473" descent="-2876" horiz-adv-x="412" vert-adv-y="412"></glyph.data></g><g transform="matrix(.0136,0,0,-0.0136,68.699,0)"><path d="M213 67C239 136 257 225 255 300C253 353 242 447 164 447C112 447 54 389 41 319L67 309C90 362 117 377 134 377C184 377 189 277 190 239C193 153 164 43 146 -12H176C278 73 450 253 450 390C450 439 410 463 396 463C384 463 380 459 382 449C385 440 389 415 389 402C389 284 312 146 216 67H213Z" id="g185-47"></path><glyph.data ascent="989" descent="-303" horiz-adv-x="454" vert-adv-y="454"></glyph.data></g><g transform="matrix(.0095,0,0,-0.0095,74.85,3.264)"><path d="M135 536C163 536 185 560 185 587C185 617 163 639 136 639C108 639 85 617 85 587C85 560 108 536 135 536ZM34 389C96 380 101 376 101 308V113C101 22 99 -37 93 -80C87 -114 80 -137 68 -152C54 -170 28 -182 -5 -190C-19 -193 -26 -200 -26 -213C-26 -237 -3 -257 10 -257C18 -257 26 -253 36 -246C59 -226 122 -150 157 -50C176 3 180 46 180 111V451C137 433 86 420 34 412V389Z" id="g190-107"></path><glyph.data ascent="989" descent="-360" horiz-adv-x="256" vert-adv-y="256"></glyph.data></g><g transform="matrix(.0095,0,0,-0.0095,77.325,3.264)"><path d="M380 106C343 72 306 56 265 56C195 56 116 112 115 248C235 252 361 262 377 265C396 269 400 277 400 297C400 374 333 449 250 449H249C198 449 144 421 103 376S37 269 37 201C37 88 109 -12 232 -12C263 -12 332 6 395 84L380 106ZM225 412C281 412 315 364 314 312C314 297 308 292 290 292C232 290 176 289 120 289C135 370 180 412 225 412Z" id="g190-102"></path><glyph.data ascent="989" descent="-360" horiz-adv-x="425" vert-adv-y="425"></glyph.data></g><g transform="matrix(.0095,0,0,-0.0095,81.356,3.264)"><path d="M298 36L289 62C276 55 253 45 228 45C202 45 169 60 169 141V397H276C289 405 292 426 282 437H169V574L155 576L90 509V437H45L17 408L21 397H90V107C90 28 125 -12 188 -12C198 -12 213 -8 230 1L298 36Z" id="g190-117"></path><glyph.data ascent="989" descent="-360" horiz-adv-x="305" vert-adv-y="305"></glyph.data></g></svg>.</div>

Mathematical Problems in Engineering

fig8

Figure 8

Figure 8: Analysis of Flow Evolution and Thermal Instabilities in the Near-Nozzle Region of a Free Plane Laminar Jet 